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





I baby dance yesterday June 21st 2019, and today my basal temp is slightly up. And I see cervical clear slippery mucus, my ovulation is between today and tommorow but it has to he today because of what i see when should I conceive? My Last period was June 9th 2019.
Hi Shanell, you can conceive any time between the 19th and the 27th of June, with the 23rd being your best ovulation, fertilization day according to the calculator. Good Luck!
Thanks!
please ma how do I Calculate my ovulation I saw my period on the 9th May 2019 and this month I saw it on the 12th June 2019
Hi Peace, just insert the first day of your last period in the calculator and the blue squares will show you your most fertile time period. This would be the ideal time to be intimate with your partner if you are trying to get pregnant. Based on a 28 day cycle your most fertile period would be June 22nd to the 26th. Good luck!
Question……..
My last period was June 1 thru 4. We had unprotected sex on 7th,8th, 12th,and 14th. According to app im to take a test between 25th and 29th. But would i show up if i take one 23rd? My app says that i should have conceived the 15th if I’m pregnant. I just hate waiting! What do you think?
Hi Autumn, your next period is scheduled to start around the 29th of June (give or take a few days depending on your cycle). I would recommend waiting until after that date to test, otherwise you run the risk of getting a negative because it was too soon, and that’s just as disappointing. Waiting is really hard but it might be your best bet. If you want to take one earlier I wouldn’t recommend any earlier than than the 24th, which is 5 days before your scheduled missed period and some brands and tests do state that you can test and get a positive that soon if you are in fact pregnant. Good luck!
Hi my last period started on 21st May, usual is 7-8 days long. Till now no sign of period, tested days ago using some house brand pregnancy test kit but show negative. Should I retest again using a more accurate test kit? Thanks!
Hi Val, they say that brand doesn’t matter, all tests run on the same principles and makeup. If you are concerned because now you are a few days late I would just wait it out. Sometimes if we are sick, medications, new birth control, travel, weight changes, diets, etc can cause our cycle to be a little bit off. However, that is normal and happens to a lot of women. Take another test and if it comes up negative and you don’t get your period soon, then call your doctor.
hello my ovulation period was from 18th of June to 22nd of June which is today and I had unprotected sex on the 20th. please is there a high chance of conceiving?
Hi Taylor, if you have unprotected sex during your fertile period, as long as there are no issues medically with either of you, then the chances of conceiving are high.
Hi, I’m Emma. I started my last period on 22 may then it ended on 27. Till now I haven’t experienced my period. It’s a 28 days cycle.
HI Emma, if you are late (which according to what you are saying you are), take a pregnancy test.
Hi am Donam I had my last periods on 25 May and I had sex on 17 June. Can I get pregnant
Hi Donam, that would have been nearly 1 1/2 weeks after your fertile period so most likely not pregnant.
I had my period last month on 25th and left on 28th but its now 18th and am in it, is this ok
Hi there, yes that’s completely normal.
hi..my last period was on may 21.. and I had unprotected sex on June 9..is it possible that I got pregnant?
hi Cherie, based on an average cycle of 28 days, you would have been in your fertile period from May 31st to June 4th, so that would have been outside of your fertile period. This is assuming an average cycle. I would recommend waiting until your next period (around the 18th) to determine the outcome or take a pregnancy test.
Hello, I very well know that I am pregnant because I last saw my periods on 19th to 21 January. But please help me know how old is my pregnancy? If I conceived around feb, when is my due date? Thanks
Hi Julie, Congratulations! Based on the conception calculator and your last menstrual period, it looks like you conceived any time between January 29t through February 6th with an ovulation date of February 2nd. This would give you an estimated due date of October 26th 2019. You are currently halfway there at about 20 weeks. This is information that your doctor should be giving you and if you haven’t seen one yet, please do to make sure that everything is going on the right track.
Hello I am Mary by name, please I am confused. I had my last period on 25 APRIL, I tested pregnancy positive the next month. That same month I had bleeding on 14 MAY 2019 which lasted for five days and after the bleeding I went back again to check myself and is still positive….pls what happened to me?
Hi Agbo, I would recommend seeing your doctor, but that sounds like you miscarried potentially. Testing pregnant right after that is normal because you still have pregnancy hormones in your body. See your doctor and they can determine if you have in fact lost the pregnancy or if you are still pregnant that everything is going as it should. Good luck.
I’m trying to conceive so I’m gonna start baby dancing June 21st according to my calculations my ovulation is june 24th so I should conceive no later than June 26th 🙏
Good luck Shanell and happy baby dancing to you!
My period came June 10th left on June 14th I had unprotected sex on June 21st when did I conceive
Hi Shelly, I’m going to assume to meant May, because we have’t gotten to June yet. However your fertile period would have been from the 20th to the 24th. If the only time you have intercourse was that day, then that would be the day considered for conception.
if I have 25 days cycle and I see my period on 17 may when will I ovulate
Hi Oluchi, You would have ovulated around May 24th to the 28th. If you want to know your next one, if your period is around the 11th of June (based on your 25 day cycle) and your fertile period would roughly be from the 18th to the 22nd.
My period date was 14 May 2019 and I had unprotected sex on May 31. Will I get pregnant?
Hi Agatha, based on a 28 day cycle your fertile period would have been May 24th-28th. So if your period is irregular and it also could naturally fall a bit earlier or later, it’s possible. If anything you will have to wait until your next period (roughly the 11th of June based on a 28 day cycle) and if you miss it take a pregnancy test.
I had my last period the week of may 26 and today its June 7 and the period is still going on?
Hello! Am kind of confused. My last period was may 3rd-6th, and on the 12th & 13th of may I had sex with my husband. wW also had sex regularly afterwards. i have a 28 day menstrual cycle. When can I go for a pregnancy test?
Hi Grace, if you haven’t gotten your period yet (June 2nd) you can always take a pregnancy test now. Your period was the 1st of June, so you can take one now if you choose. Good luck!
I was supposed to get my periods on 24th April but I didn’t get it and I had sex on 12th May with pull out method and until now I’m not having my periods. Is there is a possibility of getting pregnant ??
Hello Riya, take a pregnancy test if you suspect you might be pregnant.