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 had my period on the 5th of March and ended last on the 9th, but I had sex on the 14th of March. Now I have tender breasts which I did a pregnancy test which turned out to be negative. So what do I do now?
It is likely that you did not conceive but you need to wait and see if your period will come. A pregnancy test can be taken at that time.
I recommend you see a doctor
Hi , I would like to know , my cylce previously has not been normal . In the month of March 2016 date 3rd I got my period , which stopped after 2 days and continued after and ended after another day of getting it .. I have a 21 day cycle and my last period came the same month on the 30 or March and was not normal coz it ended on the 4th of April in that cycle aswel it stopped for a day . On the 4th last day of my abnormal period , my husband and i got intimate .. and now I cpunted my 21 days for the next cylce and I see I am a week late .. is that normal or cud I be pregnant ?
Hi Thasmera, do you always get regular periods otherwise? Irregular periods are very common and with change in life, even women with regular cycle otherwise, experience those. For now, as it is 12th May today, if you have not gotten your period already, please take a test.
My last menstruation is march 5 and he only touched me 1 time at march 26. can I be pregnant?
If he just touch you then no
I had sex on 15th April and my ovulation started from 16th April, do I stand a chance of pregnancy?
yes, because you had sex during your fertile window. please read this page for more info
Hey, I had my period on the March 29 and ended on the 31st of March and my menstrual cycle is 31 days.I had a pregnancy test a few days ago which was negative but I also have period symptoms; break out, cramps and tender breasts.
I had my period on march 5th and also March within 25-30th and that has never happened to me – two periods in one month. I haven’t gotten it in April and today is April 27th still no period. Can I please get some advice? My pregnancy test was negative.
It is possible to have two cycles in a month. You can take the test but ensure that you consult your doctor as well.
My last menstrual cycle as March 20, 2016, I haven’t had any symptoms of my period. I was supposed to come in April and it didn’t show. Today makes a week that I haven’t had a period and this month is almost over.
You need to take a pregnancy test now to determine if you’re really pregnant.
Hi, I want to know, we had sex on the 14th of March so she missed her period on March 28 means that she’s pregnant or she was already pregnant before I slept with her?
The answer to this question depends on the number of days in her menstrual cycle and if she was ovulating when you had sex. Can you confirm the date of her last period?
OK, THE LAST TIME I HAD SEX WAS JANUARY 1ST. I HAD A PERIOD IN JANUARY AS WELL AS FEBUARY, AS WELL AS IN MARCH. HERE IT IS APRIL AND I HAVENT SEEN MY PERIOD. I TOOK A TEST TODAY 4/26/2016 AND IT WAS NEGATIVE. COULD I STILL BE PREGNANT OR COULD IT BE STRESS? I STARTED A NEW JOB LATE MARCH AND I LOST A CLOSE FRIEND LAST WEEK. WHAT COULD BE THE ISSUE
Hi Nancy, sorry to hear about your friend. Yes, it can be stress. It definitely cannot be pregnancy. Wait for the next month and if you still don’t get normal period, then consult a professional. In case you are taking any medications, that might be the reason too.
hi. I am Pooja. i had my menses on 16th march. it lasted for 4 days. I had unprotected sex on 4th April and i took an i-pill on the same day at night. Now i was supposed to get my next menses on 16 april but I have not got my menses yet and it is already 26th april. Is there any chance of my getting pregnant? Please reply.
Hi Pooja, i-pill may sometimes delay the period, so it’s probably that. But do take a pregnancy test to make sure you are not pregnant. ATB!
I had sex 9 days after my period which was on the14th of april which was my period but it lasts 4- 5 days and had sex on the 22 of april which was 9 days after my period 3 days after which was the 25th of april I started seeing clear mucus discharge in my under wear I just looked this morning and its now a light yellow can some please tell me what it means as me and my partner of 3 years are trying to conceive for a baby
Hi Sharlean, light yellow discharge is often a sign of ovulation and by your date too it can be your ovulation period. In case it had a foul smell, I think you should consult a doctor. Sometimes it can indicate an infection too. ATB!
Hi, I’ve had sex on March 31 and I got my period on April 22. So my question is, could I be pregnant or not? Please help me.
It is highly likely that you’re not pregnant.
hi..just wanna ask my last period was mar.24.2016 on a 30days cycle…i had unprotected sex last march 28-29…Again had unprotected sex on April 7 but i took Emergency pills on april 8.
had unprotected sex again on april 10-11 & able to take postinor 2…
would ive be pregnant?? im waiting for my menses to come on April 24,had brown spotting a bit on March 23. Pls help, I’m so depressed already. Thank you.
Hi Joanna, Have you got your period by now? As you took emergency pills, conceiving has a very low chance.
Hi, so I have no idea what is going on. I usually start my period on the 20th to 28th but last month I started 3 days late and only had it for 3 days so march 23 to march 26th. I took a pregnancy test around april 15. It was negative and then i started my period on april 23 again. Can anyone help me?
Hi Alexandria, this is one of the changes most women experience during life, it’s nothing to be worry about. I don’t think pregnancy is playing any role here. It’s just natural.
Hi I had my period last March 7, 2016 up to March 14. Then after 21 days I got my period again March 27,2016. It was my first time to had a menstruation after 21 days. I had one unprotected sex last April 16, 2016. I usually had my periods 28-31 days.. and it’s the 29th day today I still never had. I tested for pregnancy test since the day I had sex and today..it takes me 5 pregnancy test from April 20 up to now and it says negative. IS it still possible that I got pregnant? Pls help.thank you
Hi Jemma, First, pregnancy tests should be taken 10 days after you miss your expected period date, otherwise accuracy may be less. Then, going by 28-31 days, your period should be on 25th April, so probably you have got your period by must now. If not, then take a pregnancy test after 2 days from now. ATB!
Hello, I had sex April 1-5th. My last period was March 26th. Could I be pregnant?