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





Plz someone help, my cycle is usually 36 days. My last few periods have fell like this. July 15 Aug 19 sept 23. I was suppose to start Oct 28, but didn’t. Had mild cramps like my cycle was coming but nothing that day. Nov 1 mid day I started to see blood. For my self it was a very light flow. And a pinkish color with a kind of clear slick tint to it. Today I get up its still very light flow for myself as well as darker blood. Usually with my period coming on the first day I have cramps not extremely bad. But I feel them. These feel like nothing compared to that. Did my body just skip oct period or what??
Any advice will help.
Hi, Any Unusual bleeding that does not seem like a period should be checked out by a doctor,i don’t think its anything to be worried about but if your period didn’t show and you are bleeding lightly i suggest you go to the doctor.
I normally have my period after 21 days of my previous. But it seems different as I last saw my periods on on the 9th October to the 11 October. and now I’ve started my period on the 2nd November. It did not reach the 21 days. I’m kind of worried. I’m I pregnant or what? Pls advice. Thanks
Hi,Short period is not a sign of pregnancy, but if you are in doubt whether it was a normal period, a home pregnancy test should answer this question for you.
Hello….
I had my periods on 17- 20 october….and the menstrual cycle calculator says that my next period is probably on 14th november and that am fertile from 29 october to 2 november….and i want to do sex without getting pregnant so when are my safe days to do sex with my boyfriend because i have irregular menstruation cycle,please help….Thanks in advance
Hello, To be honest you can get pregnant at anytime during the month so i advice you consider birth control to make sure you don’t get pregnant because if you do not consider a birth control and have unprotected sex with your boyfriend you will be back on here worrying if you are pregnant.
hi,
i don’t have cycles that are the same number of days from month to month. So, i range anywhere from 26 to 30 days (for the past 8 months of observing my mens cycle). Now, I had sex with my partner last October 25, 2015 through pull out method and my last period started October 7. I don’t know when my ovulation days are. I don’t know when exactly my next period comes. I’m quite paranoid for the thought that i might get pregnant. but is there really a high chance?? what’s the likelihood? please answer my questions! thanks!
Hi, There is a high chance of pregnancy anytime you have unprotected sex as pre cum can get you pregnant hence, the withdrawal method is not a safe contraceptive method to be used. Take a pregnancy test in a week or 2 to be sure.
Hi my last period was on da 09th October 2015 then I had sex with my boyfriend on the 15 October then on 21 October I had sex again with another person my cycle is 21 days I suspect that I’m pregnant but not sure who could be the father
Hi the first day of my last menstruation period was September 30. I am afraid if I am pregnant as I don’t have my menstruation until now. Can’t determine my monthly cycle as it always vary. Please reply. Thank you.
Hello. I saw my period last on 7th Oct and I have a 22 days circle. When next should expect the next period. Thanks.
Your next menstrual period was expected to start on October 29, 2015.
September cycle began on the 13th october it began on the 7th. When is my next one
Hello…so on Oct. 25 I gave my boyfried a bj then swallowed and then wiped his lenient on my chest and then made out for a while like 5 minutes and then I got on top and we did a few “pumps” (you know what I mean). No condom and then got off and neither one of us came at all that. I am due tomorrow but I just want to know is there any way that I could be pregnant if my fertile window was Oct. 16th – 20th. That was our first time ever doing that so we wanted to know. Please quick response!!!!!
It is possible that you did not get pregnant since you were well outside of your fertile window.
Hi, Its possible you can be pregnant if he pre ejaculated/pre cum inside you,if not you are safe .
I started seeing stains on 2nd of October then on 3rd it was flowing heavy when am I supposed to see it again
Hi I had my period on 29 september and had sex on 3 October which is a day after my period and I also had sex on 10th and 11th October which was my ovulation my next period was on 27 October but I’ve missed it for four days now and I’m really confused I’m I pregnant?
Hello. It is possible that you conceived. You can get the most accurate result if you wait at least one week after missing your period before taking a pregnancy test for confirmation. In addition, the result might be even more accurate if the test is done first in the morning as the urine is far more concentrated at this time. The urine-based home pregnancy tests offer great accuracy. T
Hey so my last period was on September 19 ended on 22 and I’ve had lots of sex with my hubaby as we are newly weds. I’ve taken several tests some too early I’m sure but most recent was Friday and was negative. When should someone get a blood test I have pcos and we’ve been trying for 2 1/2 yrs.
Hello Kate, Blood tests can detect pregnancy from about six to eight days after ovulation.So i think you can go in for one anytime after ovulation.
My last menstrual period is July 3 2015 to July 7..my expected next period is August 2..I had sex with the first guy on July 14 using withdrawal method or pull out ..and had sex with the second guy on 17-21 July with unprotected sex.. which of them is the father of my baby? I’m pregnant now. Hope you can answer this. Thank you..
Hi, The only way to be certain is to have a DNA test because no one knows for sure the exact time you conceived.
Hi my fiancĂ© and I had unprotected sex when he come home from military training 9-5-15 we had sex when I was on my period. The next day my period was done and we had sex multiple times the next 3 days. I was on birth control and I stopped using it a couple days after he left.. I haven’t had my period since the last time.. It’s been 7 weeks. I keep taking tests but they come out negative.. Idk what’s going on and need some advice? I did have some spotting on the 24th of September but I thought it was my period but it only lasted 2 days.. I recently had spotting again yesterday and the day before..
Hi Anna, I think the best thing to do is visit your doctor it might not be anything to orry about but just to be sure.
Hi. I got my period on the 28 of September, had sex the 19 of October and I haven’t got my period since. I am wondering if I am pregnant because my period was supposed to come on the 26th and it’s a no show.
Your period is already late by four days. You can get the most accurate result pregnancy test results if you wait at least one week after missing your period. In addition, the result might be even more accurate if the test is done first in the morning as the urine is far more concentrated at this time. The urine-based home pregnancy tests offer great accuracy.
Thanks steffy,I will definitely do 1 in a weeks time. Its a bit scary thou wondering if your pregnant or not being that I have low womb,I stopped lifting things,stop bending etc just in case if I am pregnant. I am so anxious in finding outvge result
Hi, my period is the excalty the same , except mines came November 1,2015 but I’m not sure What it means because missing a period never happened to me before mines is just like clock works.. And I didn’t have October period at all. Please help.
It is normal for women to have a missed period without being pregnant. There are many reasons that could have caused you to miss a period read more at this link http://womanjunction.com/missed-menstrual-cycle/
If I had my period on the 7th of October would I be due on today? I’m normally 22 to 24 cycle. Thanks in advance.
Using our calculator at http://womanjunction.com/ , with a 22 days cycle your period would be due on October 29. A 24 days cycle would be due on October 31.