You want to know the dates of your next period, ovulation or due date? You came to the right place. If you’re in a hurry you can go straight to our menstrual cycle calculator (click here) or Infographic with key information about calculating your period (click here).
Check the full table of content below.
Table of Contents
- Introduction
- Period & Ovulation Calculator
- How Do Menstrual Cycle Calculators Work?
- Using a Period Calculator
- How To Calculate Your Next Period & Ovulation Infographic
- Understanding the Menstrual Cycle Properly
- Understanding Your Next Menstrual Cycle and Fertilization.
- Some Important Information Regarding the Calculator
- Learn more
- Frequently Asked Questions
Introduction
If you want to stand the best chance of getting pregnant, then you need to know when you are ovulating. This is the time of the month when women are in their most fertile period. Ovulation usually happens around day 14 of the cycle [1]), while there is a greater chance of a sperm reaching the egg and fertilizing it.
However, one of the biggest problems and question that people have is knowing how to calculate their next ovulation date and when is the best time to aim for intercourse. This is where technology can come in handy. You can use an ovulation calculator, like the one below, to get a rough estimate of when you are going to ovulate next.
Ovulation & Period Calculator
Use this period calculator to calculate your next period (menstruation), fertile period, ovulation, and due date. To give you an estimate as to when those time frames are, please provide the requested information and press the Calculate button (results will be shown below, together with a fertility calendar):
When did your last period start?
How many days did it last?
How long is your cycle?
Below are the results based on the information you provided:
Your next menstrual period is expected to start on
Your next most fertile period is from to
If you conceive within this timeframe, your estimated due date will be
- Pre-Period
- Period Days
- Post-Period
- Peak Ovulation
Please note that this is only an estimation of your menstrual cycle
A period calculator is not the same as talking to a healthcare professional, so this is just to aid you in coming up with the most accurate calculation possible, on your own.
Also, keep in mind that these calculators will be useful to women with a fairly regular menstrual cycle. For women with irregular menstrual cycle tracking other ovulation symptoms or using an ovulation predictor kit might give more accurate results, all of which we’ll cover later one.
How Do Menstrual Cycle Calculators Work?
Menstrual Cycle Calculators vary in complexity. Some will ask you for information such as your average body temperature, as well as various other bits and pieces about what your body is currently going through.
While there are women who measure their basal body temperature, it’s not something that the everyday woman uses.
However, it is a rather accurate way (when done 100% correctly) to determine when a woman is ovulating.
Some feel that these types of cycle calculators are “overkill”, but for those who are using the basal body temperature to prevent and plan a pregnancy, they have this information handy.
If you aren’t into this type of strict monitoring, a simple calculator like the one provided here can give you really good results and help you plan.
Using a Period Calculator
The first thing that the period calculator will ask you is the date of your last period. With so many apps available now, this should be information that is readily available.
And just remember, when calculating your period, you use the first day of your last period. This was the beginning of your cycle.
If you don’t know the exact first day, calculate back from the last day however long it lasted, and start tracking now. Especially if you are trying to get pregnant.
Some will use a menstruation calculator to figure out when to expect their periods and when to expect PMS. PMS is due to the change in hormones that cause periods and pregnancy.
When you are pregnant or during your period, these emotional and physical symptoms subside [2]. Some women can then plan to change their diet a few days before they expect PMS and help to alleviate some of the symptoms.
The next piece of information that you will be asked for is the average length of time between your periods. This is the length of the menstrual cycle. Of course, the human body does vary wildly here, and whilst some months there could be 30 days between your period, others it could be as low as 25.
However, you are only after an average here. Being as accurate as possible is important as this will affect the results that you are given which can have a profound effect on when the calculator tells you is the ideal time to try for a child.
Finally, you will be given your results. Based on the information you provided, it will calculate when your next period is anticipated and also your fertile period which is when you stand the best chance to get pregnant.
How To Calculate Your Next Period & Ovulation Infographic
Understanding the Menstrual Cycle Properly
While you may already have a fair understanding of your own menstrual cycle, there are women who have cycle lengths that vary. Sometimes, your own cycle can be as short as 23 days on cycle and 28 or 30 days the next.
When a variation in menstrual cycle length occurs, it usually happens before you ovulate. This is referred to as the follicular phase which encompasses menstruation as well and ends when you ovulate [3]. A woman generally ovulates between days 12-16 of their cycle which is the start of the luteal phase [4].
There is a multitude of reasons as to why your period could be altered, be it stress or medications, even weight gain/loss or travel. Unless you think you are pregnant, it could be a myriad of reasons that have your period coming irregularly.
Understanding Your Next Menstrual Cycle and Fertilization
If you are trying to get pregnant you need to understand how the menstrual cycle works. The process starts when the thick lining of your womb starts to break up due to the decrease in estrogen and progesterone levels.
Without a sufficient amount of these hormones, your body will shed the lining and it will start to prepare for your next menstrual cycle.
However, if a sperm does make contact with and fertilizes the egg, it will close all pores to prevent more sperms from getting in there. The fertilized egg will stay in the fallopian tube for 3-4 days and then move to the uterus and attach to its wall, staying there for the long haul of pregnancy.
Your body will produce human Chorionic Gonadotrophin (hCG) or pregnancy hormone right away (which can be seen within 6-8 days by a blood test and can take about 2 weeks if not longer to be seen in urine tests) [5].
The body will continue to produce the required estrogen and progesterone hormones so that the womb lining will not be shed and the placenta can grow mature enough that it can support the pregnancy.
Some Important Information Regarding the Calculator
The period calculator above also comes with a fertility calendar. You can navigate through different months by clicking on the NEXT 2 MONTHS and PREVIOUS 2 MONTHS links. This allows you to plan and prepare for your fertile and menstrual periods in the upcoming months.
What you do need to remember though is that the information isn’t 100% accurate as it is impossible to predict the human body.
Your fertile period gives you a good range in when to have intercourse to potentially get pregnant. You can learn more about the likelihood of conception in this article.
That being said, the menstrual calculator is still an extremely useful tool. It provides a simple way of knowing when to anticipate your next period and when is the best time to try for getting pregnant.
This could be a huge help for those with busy schedules to plan their days to start their family.
Learn more
Want to learn more about your menstrual cycle? Find out how does the Fertility Calculator work or how to to calculate your period manually.
Want to know if you’re pregnant? Take this online pregnancy test, read more about the most common reasons why your period might be late or find out when it’s the best time to take a home pregnancy test.
FAQs
How do I calculate the length of my cycle?
Can I have sex during my period?
What is the average length for periods?
My period is really heavy; what can I do to change that?
Can I get pregnant if my periods are irregular?
How do I know if I need to see a doctor because my heavy periods?
Can I prevent PMS?
Do you have any other question about your period, ovulation, pregnancy or other related topics? Check out our Frequently Asked Questions page.
References
- Your Fertility. Women’s Guide to Getting the Timing Right [link]
- Mayo Clinic. Premenstrual Syndrome (PMS). [link]
- Better Health Channel. Menstrual Cycle. [link]
- see above #3
- WebMD. Pregnancy and Conception. [link]
- Eleanor Jones via Cosmopolitan. 10 Questions Period All Guys Want Answered [link]
- Playtex. Period 101. [link]
- The University of Iowa. Birth Control Pill Fact Sheet. [link]
- WebMD. Slideshow: Answers to Your Top period Questions. [link]
- see above #9
my last period date is 27th of December last year, I had sex on 9th and 11th of this month, is it possible that I am pregnant
o wow that’s scary my period was Dec 27 2014 my period comes ever 27 days I also had sex the 9th and 11th of January period was due Friday 23 only 4 days late waiting until Friday to test
i started my period on the 20th of december 2014, had sex on january 10th 2015, at 3am it is now january 23 2015 no period yet , just wondering what my chances are of being pregnant
Hi
you were into an early fertile window, odds are positive. Test yourself, you are indeed late !
Good luck
Hello again thank you for replying.. i had forgot to mention that i am on a 32 day cycle but am waiting till at least another 2-3 days an if nothing happens an i don’t get my period i will go and take a test.. i have been anxious an not sure if that is something that might bring on symptoms or over thinking i might be..
also januray 10th was the only day i had sex in over a year, so if i am, im thinking i might be about a few days to maybe a week pregnant
My last cycle was Dec.4-9th 2014 and here it is Jan.23 and my breast are sore and I’m constantly feeling sick to my stomach..can I be pregnant I don’t want to take a test then it says negative but if I am this will be my second child
Hi,
If you did not had your january periods … I would take a test … as you are indeed deeply late. And … better to know then to wait until you have no leverage on the decision to take on the future of a possible pregnancy
Good Luck
My period last month is April 7th 2015 but i still don’t have my period May 7th and i had protected sex May 11th. Until now i still don’t have my period. is there any tendency that I’m pregnant?
Hi I had my period the 22/12/2014.I had unprotected sex 2 days after my period that the 27.my fertile days was 3-7 of jan I had unprotected sex the 7th of Jan on my fertile day. I was having period like cramps from the 29 of dec on and off come right up to the 17 I took a pg test 7 days after the 27 it was negative. I have abdominal pain, eat a lot, pee, am tired during the day but can’t sleep. my left breast is swollen my mouth is fresh I feel stomach cramps feel bloated. Each time.
I eat I feel like I want to throw up I also feel gas I also had unprotected sex on the 18th of this month, 2 days later I had something like period please I need help can someone help me
Take another pregnancy test. If you don’t want a baby I would suggest using protection, you appear to be having alot of unprotected sex. I don’t mean this as a judgement.
Hi,
everything is possible but the last day of your fertile windows is the most probable one that could be triggering a pregnancy, but … your symptoms can hide something else. Please test yourself home, it is negative, I strongly recommend you to visit your physician for more answers.
Good luck
Hi I’m new here. I’m 27 yrs old. I have 3 children. 6yrs 4 1/2 yrs & 14 months. My periods r usually right on time. Or 1-2 days off accuracy (early/late) on due dates. In November 2014 my period was the 2nd. December 2014 it was the 1st. So that’s a 29 day cycle if I’m correct. My last period was December 27th 2014. My husband & I do use protection (condoms) but sometimes we dont. We wouldn’t mind if we became pregnant again. & we have had unprotected sex 3 times this month. (January 2015) its now January 25th 2015 & I still haven’t gotten my period. I took a test on 1-23-15 it was Negative. & then I waited & took another 1 last night & got another Negative. I’m bloated, nausea, more tired than usual & craving things I normally wouldn’t crave. Like Pastene peperoncini pepers in vinegar dipped in peanut butter. Could I possible be pregnant & just testing to early or is it just my mind playing tricks on me? Please help me.
Hi ,
it ia too early to have craving if you are pregnant, having the experience of 3 pregnancy already can indeed trick you ! you should test yourself around Jan 30- feb 1 st, before it will give you uncertain result, as you would not be late ..
Good luck
hi i had my period on the 21/12/2014 and i had sex on the 25 through 27 and this month i have not had my period yet please what should i do
Hi abigail, I think you should go and see your doctor or do a pregnancy test at least
Hi my period is normally 28 days and my last period was 12/20/2014 and my period still hasn’t came on. I took a pregnancy test on the 1/18/2015 and it was negative. But my period still hasn’t came on..I do not take birth control or any contraception all my life so my period comes like clockwork. I have some cramps like my period is coming on in the morning but no sign of bleeding. Could I be pregnant?
Hi,
a pregnancy is possible indeed, as skipping a cycle. Numerous factor in life can affect our cycle and miss one, such as, new job, new diet, gym, stress of any kind. You tested yourself early, I would recommend you to test it again, use the first in the morning urine it is always the one containing the highest concentration of HCG, the hormone targeted by the test. If it is negative again and that you still have odd symptoms dont hesitate to consult your physician for more answers.
Good luck
I get my period every month on the 20 and the 21 but last month I got it on the 17 and this month I still haven’t gotten it but I took a test yesterday and it was negative
Hello I had sex Dec 24 2014 had a two day period beginning Dec 26 2014 I have still not started what do you recommend?!
Hi,
period length may vary, especially with the holiday season with the gatherings, lack of sleep, even new gym resolutions can change your cycle. If you are use to take any kind of birth control I would not worry as 2 days before your periods, it is far from your fertile window. But no guarantee as sometime life find its way !
Hello I would like to know if it’s possible to get pregnant the last day of ovulation?
I had my period on Dec 10th 14
Supposedly ovulated on the 30 to January the 5th were my fertile days… But I only had sex once on the 2nd of January around 1am… Could I possibly be pregnant? If so I should
Be 4 wks and 5 days… & do have all the symptoms but I tested at exactly 4 wks
& test was negative…. Should I retest? & when?
Hi , odds are minimal, conception is not an exact science and a matter of minute can make a difference between a fertilisation or a fail. Conceiving required a bit of planning and cannot be settled last minute. But indeed life is always finding its way. As of your pregnancy symptoms, sometime we are so wanting something that we are listening to much to our body and psychologically creating these symptoms …. if the test is negative , 4 weeks after being late… it will keep being.
Hello, My last period was on 12/19 and my cycle is normally every 28 days. I have had intercourse on my fertile days and from the calendars my period was suppose to come on the 15th. How late can my period be?
if you have a 28 days cycle your period are due on the 17-18. If they dont come, test yourself !
good luck
hi, i had sex on 14-12-2014 and never took my prevention pills then 20-12-2014 was my last period is the any chances to be pregnant?
I saw my last Period 12/16/14 and today is 01/16/15 nothing yet! Is it Preg??
Hello, had mp on 29/9/2014 had sex 5 days to my next period October which came 26th instead of 27th. My November period was suppose to b on 24 but i started spotting on 21-23 den my period came on 24th-29th. In d month of December it came heavy for 2 days and spotting for 2 days 20-24th. Am scared because I feel bloated, bubbling on the Left side stomach and foamy urine. Have had 3 HCG test previously and one this morning all came negative. My next period is on the 17th of this month.
Hi , obviously you have a short and irregular cycle, I don’t not really understand your concerns. You can always discuss the possibility of taking a birth control pill to set your cycle to be more predictable.
good luck
Tnx for the reply. Had my period from 17-21 January this year, but still have same symptoms lyk kick and gurgling on the left side of my tummy. Plans to go for scan this week.
My period came on December 10 2014 I had sex a lot after that but my period have not came yet for January when should it come this month I take a pregnancy test but was negative so how long should I wait
Hi , skipping a cycle can happen without being pregnant. Stress, new year resolution, dieting gym, new jobs … there so many reason for your body to skip a cycle. If your next cycle is skipped and the pregnancy test still show negative, I invite you to have an appointment with your physician to get answers
good luck !
I had my period Dec.10 and didn’t have sex until Jan. 1 but my cycle still hasn’t come on could I be pregnant
HELLO I HAD MY PERIOD 12/18/14 AND ITS 1/12/15 IS IT LATE. OR WHAT MY BREAST FEEL A LITTLE TENDER AND THATS ABOUT IT
Angela, me too! Oh my god I found some with the same issue and with almost the same dates as Me. My last menstrual cycle started 12/16/14 to 12/21/14 and the last time I had intercourse in December was on 12/22/14. Then I haven’t had any intercourse until 01/05/15. This past Saturday 01/10/15 I was supposed to start spotting as I always do and two days later have a normal flow. I Sunday 01/11/15 my breasts hurt so bad I flinched. Itself like someone to a needle and poked me in my left breast and now both breasts remain tender and I get sharp pains often. I also feel I’am getting white thick glue like discharge on my underwear and I took a pregnancy test yesterday at the hospital and it was a negative. They said it might be to early to test. The nurse recommended I wait till the 28th of this month. I am excited and terrified. I ask feel more tired than usual. I usual workout but since Sunday I have felt fatigue. This will be my second child if I’am pregnant. Will update on the results. Please share yours too! 🙂 good luck!