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





Hi
I got my last period started on 22 April, (last month). After a week I found a light spot of blood on my salwar ( cloth )..This happened 2, 3 times. Now on 13th may , my menses period started again. Can u help me to regularize my period cycle. .mu age is 40 years
Always greatful
My last period started on the 31 March 2015 and normally lasts for 4 to 5 days. Up until today didn’t have my next period. Is this possible??
Hi my last period is on 28 march 2015. Until now i’m still waiting for my next period. Does that mean I’m pregnant? How soon can i test a pregnancy kit? I’ve been married for 4 months and trying to conceive. Please help! ):
Hi! As of today, the 15th you could possibly be pregnant! Usually you can test about a week after expected period. Its been more than a month, so yes! Buy a test and good luck!
Hi my LMP was on april 25th got 3days periods usually.. had sex with partner on 6th day of the cycle but ejaculated outside 2 times. got my ovulation on 13th day. is there any chance of pregnancy please reply
You could very likely be pregnant. A man leaks sperm during sex so thousands of sperm enter you when having unprotected sex.
Even though your partner can still impregnate you from ejaculating within the vaginal area, it is unlikely that you are pregnant since you were not yet ovulating at the time. You had intercourse within 7 days from the start of your cycle and you have a lower chance of getting pregnant before you begin ovulating (which should be around the second week of May) as indicated so it’s unlikely.
Had my period on 26th of march,saw the one of last month on.24th of April…plz what could be my cycle length….28 or 30 days cycle?
Hi! Your best bet would be to use a free cycle calculator. You can try one at the top of the page
Good luck!
Hi.. plz help me.. i had unprotected sex on 20 march and got my period on 25 march and 19 april.. am i pregnant??
If you got your period then you’re not pregnant
I want to conceive on this month. My last period was on 12 th APR 2015.
Please let me know when should i do a pregnancy test
Hi last period was 7 April 2015 and I was it again 9 of May is it normal
hi ….I started my last period on May 5th and i want to get pregnant, which days will be my fertile days
I had my last period on 22nd March and I haven’t had a period since then. I had diarrhea 2 days ago and now I have been constipated for 2 days. I also find myself spitting a lot and can’t control the saliva. What do you think this could be. Please help if you can
Your period was due in April around the week of the 19th and you’ve missed your period. If you’ve had unprotected sex after your last period, it’s best to take a pregnancy test and see your doctor. Though less common, the others are symptoms of pregnancy as well.
Spitting – Some women report excess saliva which is due to hormonal changes; and
Constipation – Pregnancy hormones will slow down bowel functions to give maximum absorption time of vitamins and nutrients.
While this may not be pregnancy, your body may just be dehydrated or under stress. Please see your doctor if these symptoms persist.
Pls help me out, i saw my peroid on the 26 of April (last month) when will i start ovulating? Or will the ovulation come 8 days after the menses. Pls i need urget help. Tnx
Your fertile days and the ovulation to be precise will come around 15th day after the first day of your period. I can only calculate exact dates if you mention how long is your cyclus. Mostly women have a cyclus around 28-30 days, but there are also much shorter or longer time spans.
Hi I usually have a 28 days cycle my LMP was on april 25th and contacted with partner on april 30th but ejaculated outside 2 times.. I felt ovulation pain on 7th may . Is there any chance to get pregnancy .. or sure about next periods
Hi I have a question for anybody that has an answer. My last period was March-14-2015 and I had unprotected sex the day before my period was due, now I’m super late & it’s now May 2nd is there a chance that I could be pregnant??
Well, month and a half is pretty long period but one day before period is a very unusual way t get pregnant. It is extra rare so I would suggest that you check for any other reason why your period is missing besides pregnancy. I would also take in notice if I had sex before during the previous fertile period.The hyper-production of the ovaries is very rare so I would check the reason number two.
That for me is not safe. Back in 2006 I know a couple who had s*x when the woman had her period.The result the woman pregnant. I suggest you get a pregnancy test.1 month delayed is very alarming unless you are having a hormonal in-balance.
Hi am Enny and am 37yrs, i always have a regular cycle until recently in the past 3 months started noticing my cycle dates are getting shorter. Have been so worried. Last month I had my last cycle on the 11th of April and am very surprised have started another one on the 1st of May . I felt the discharged by 30th of April which brought our slight stain of blood but by the next morning i already started having flow. What could be the problem of the early or change in cycle?
The length of the cycle can vary for so many reasons. I would check your general health condition and hormones. Sometimes it is a natural thing, probably even hereditary. It doesn’t necessarily mean that you will have the same period cycle the whole life.
Hi! I had my period on 3/18 it was reg. When it came 4/14 it lasted 2 1/2 days. Took a home test yesterday 4/28, and got what seems to be a faint line. Could I prego or am I tripping???
If the results of your home test showing positive for the pregnancy, then the test detected the hormones that are usually connected to the pregnancy. If you usually have the longer and ( more) painful periods in comparison to the previous one then I would suggest that you go to the proper check.
If my cycle length is 26 days my last period started dec 19 when did i ovulate. I had sex jan 2 and my pregnancy test was positive jan 15
Your fertile period was from the December 29, 2014 to January 02, 2015, but as you have had sex on the last day of your fertile period it seems a bit extraordinary that you got pregnant exactly on that day. Also, the pregnancy tests are usually very inaccurate in an early phases of the pregnancy and usually they come out negative. I think that a doctor will determine an age of your baby with the ultrasound in less than 5 minutes.
I started my last period on March 28, 2015 and it is April 28, 2015. I have not started.. Could I be pregnant??
HI Curios1
March 28th 2015 was also my last period. It’s the 30th now and still nothing. have you got your period yet?
How many days cycle are you?
My last period was March 29th and I never thought about it till today that it probably
period should’ve started and I am going to Vegas next week and doing a wedding photo redo for are 1st aniversary I been working out, i couldn’t fit into my wedding dress and haven’t been able to lose any weight just maintaining it. so all of this is short story my sis made me take a test today and it was as pos as could be! Talk about total shock
It’s only have been a month between your periods, but it can be a false alarm. If you are curious and you can’t wait I suggest you that you visit your doctor because tests won’t tell you much. At least the results won’t be accurate or reliable because it is too early.
You can’t really know if you are pregnant or not only because you are 1-3 days late. If you have a period that lasts 28 days you might get pregnant if you had an unprotected ( and successful) intercourse with your partner during your fertile period, between April 9 and April 13. Add around 2 days that spermatozoids can survive inside of a female body and it adds up a period from April 7 to April 13.
i got my period on march 29.my expected period date is 26 April.It was missed.So i checked pregnant test on Apr 27 early morning.It is negative.but still now i can’t get my period why?