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





Im just sent my email…. Can I asked when can I get the answer because im little bit worried now if still possible to get pregnant even the menstrual period came already…..my boyfriend keep asking me if I am pregnant already……
Hi guys, I got sex with my boyfriend last may 6,2014 then my menstrual period came on may 19,2014 is it still possible to get pregnant? Thanks
Hi , being pregnant from the intercourse you had on my 6 th, odd that are that you cannot be of you had your periods, a small percentage of women have period like bleeding on the first trimester, if you have a doubt the best way to know it is to do a pee on a stick test, by now the concentration of the HCG, if you are pregnant will be more than obvious on the stick.
Good luck
my last period was April 19, 2014.. i started taking pill on May 1, 2014 and had sex with my bf on May 17, 2014. and my expected date menstruation will be May 19, 2014 but as of today no sign of menstruation.. can i get pregnant of that days i stated?
HI , your cycle will change completely with the birth control pill, the pill takes 7 o 14 days before being fully effective , period where the doctor most likely recommanded you to still use condoms. depending when on your cycle that you started to take your pill, the controlled hormones in the pack should make you starting your next period on the 28 to 30 days after the first pill you took. If you feel anxious about the possibility to be pregnant a pregnancy test is well indicated. As that stress can delay your period and make you stress even more.
Good luck
Hi. I had my regular menstruation on March 30-April 5. I had sex with my partner between April 6-17. We used condoms sometimes but sometimes we only used the natural method of withdrawal. Then on April 19-29, i had an unusual menstruation again. It was so heavy that it lasted for 10 days. From then on, i was having abdominal and pelvic pains, even up to now. But the pain is no longer that bad. I should have my period anytime from now but the calculator said i should have my period by May 17. Could i be delayed and pregnant?
Hi , first of all if you are not wanting to get pregnant the withdrawal method is far from being the safest choice and can cause you to be in constant stress or the arrival of your period in order to confirm that everything is fine and that you are not pregnant … which is enough to delay your cycle. By now the best solution will be to clear your minds by doing a pregnancy test. Good luck
hello.
I had my last period 15th of last month, then on the 10th and 11th of may I had an unprotected sex with my boyfriend, and the on the 12th I took postinor 2 to prevent pregnancy. my period for this month was supposed to come on the 14th but still no sign and Am beginning to get so worried. What should I do Please.
Hi , bu now taking a pregnacy test will be your best bet. Often emergency birth control also disturb the regular menstrual cycle as well. Good luck !
I had my last period from 24 march to 29 March.and had unprotected sex on 7th of April. I have a 30-32 days menstrual cycle usually. Did not have a period till now. Got urine pregnancy test today evening. It was negative. Are there any chances I am pregnant.
I had my period January 3rd and that lasted til the 8th. Then I started spotting on the 16 and that lasted til the 17th. And again on the 28th and that lasted tillthe 29th. I have taken 10 home pregnancy test and all came back negative, but I went to the doctor who also gave me a urine test that cameback negative so she scheduled an ultrsound and she showed me my baby and the little heartbeat. And I was on the birth control shot. So this will be my sencond child my first is almost 9 months.
My lmp was March 28-31 calendar said ovulation was April 8th suppose to have a period on the 22 or the 23rd spotted on the 24th, no bleedy pad, clear secretions only. Took test, it was neg… I feel bloated and breasts been sore for over 2 weeks, been feeling feverish. How long should I wait out to take another pregnancy test? Is too soon to take it? Should i wait till next week?
I would wait 7 days and do another test with the morning urine, to have a clear result. Listening to much to your body can mislead you into a wrong path symptom… you more have ovulation symptom then pregnancy ones to me ! Look into your cycle length as most test are custom for 28 days cycle.
good luck
I and my patner have been trying to have a baby but proved futile..had my menses of 7th May n expecting it on 4th June bt a spot of blood on the 2nd June…..might I be pregnant…
Guys again i have no idea what’s goin on with my period . I got mine last month on the 18th march its now the 24th of April and still no sign.one thing i will say i did think i got them on the21st because when i wiped there was blood turned out i it wasn’t my periods.then yesterday i spotted again briefly…im still waiting for them to come so i can get tests done with the well woman centre…also since the 19th April i have been highly strung and stressed mayb this is y there late too…i just wish they were regulated.as in 14 years they have never been on time.
Hi Bjane87
A big amount of stress can make you skip one or more cycle. you can have spotting or near nothing just a bit of dark browning trace on a wipe due to a very slow leakage. More you will stress with this on the top of the stress you already have to cope with , more irregular your cycle will be. Try to be Zen !
good luck
My girlfriend see her last period on 31 last month and I have sex with her on 20 of April; will there be any chance of she getting pregnant. Please I need your help.
Hi Leh,
chances are little but it can be depending of the length of her cycle. Protection is always the best way to avoid being worried about an unexpected pregnancy.
Good luck
Pls i need ur help,i usually have my period done for 5 days but last month it started on 16th and i had sex on 18th and it stopped coming so it only lasted for 3days and according to my app calculator my period should start this month on 13th but it didn’t come until 18th and it also lasted for three days pls what could be happening?
Hi T girl !
I don’t know how old you are and if your cycle was regular but it happen that the cycle will change for a more or less regular during a women life. More volume less volume , barely dripping or a flood .. You understand what I mean .. also having sex during your period is not a guarantee of no pregnancy depending if you had already ovulated ,or had a second ovulation.
good luck
My last period was February 28th-March 2nd. Today is April 14th and I haven’t gotten my period. I took 2 at home pregnancy test both were negative. I am 31 year old latina, I’ve never been pregnant. Could I be pregnant?
Hi confused !
As you know all women have different cycle length normally between 28 to 32 days. The day your period start is the day 1 of the cycle , you are fertile between the day 12 and 16 depending of the length again of your cycle. Certain test are efficient a few days after the period lateness other takes some time. Other reason as sport and stress might had an impact on your cycle and make you skipping a period. My recommendation is to wait 7 days before doing another test and do it with the first morning urine. The concentration if the HCG is higher.
Good luck !
i had my period on 13 march so i am confused whether i am pregnant or i have 2 wait for next period
my wife had periods on 28th march 2014 and was completed after 7 day but today she told me that she has pain and thinks that she is going to have periods again so kindly tell me is this concerned with conception pills or its natural.
my expected most fertile period is March 25, 2014 to March 29, 2014, but if I had sex last March 14, 2014 which is the last day of my period, is it possible that I would be pregnant? I’m still expecting for my period tomorrow March 10, 2014……what should i do if it would not come tomorrow..?
Hi my last period was on Feb 9 2014 at night I was back in India for month i came back here on Feb 11 2014 it’s been almost 2 months I didn’t got my periods it is possible that I could be pregnant me n my husband trying to have baby for past 6 months pls help me ??????
It is absolutely possible that you could be pregnant. Did you take a pregnancy test? Travel and changes in diet and water, can contribute to disrupting or skipping a cycle or cycles, though. It is best to test and check with your physician.
This doesn’t pertain to your question but I am trying to get pregnant and I had a cycle on April 1st 2015 and ended on April 5th and I had sex on April 15 what are my chances of being pregnant
I was taking the mesigyna injection but did not take it in April. I had my period 04/07/15 which lasted until 04/11/15. My partner and I had sex uprotected about the 18th and now I have not had my period since May. Is it possible I could be pregnant?
yes i would take a test! i have the same problem i had my last period july 30th till aug 4th and i still haven’t had any periods yet
I’ll take any opinions from any and everyone! My boyfriend nutted in me on March 27, 2014 but my period came on on March 27, 2014 . Today is April 5, 2014 . Could this period be the last period and can I still be expecting to become a happy first time mommy within 9 months?
It is possible that you are currently pregnant, but not very likely. It would be more likely to have happened during your fertile period about five to fourteen days before your period started.