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, my last period was 18 October had sex 21-23 October I have a cycle of 23 days ovulation calculator says my fertile period was 25-29 October. Is there any chance I could be pregnant. I had slightly sore breasts soon after ovulation, but everything has disappeared now. Hoping to be pregnant.
Having sex on your fertile days (October 25 to 29) would give you a greater chance of being pregnant. You had sex outside of October 25 to 20 so the chances would be low. Your next period was due on November 10, take a test one week after this date if your period does not come at that time.
Hi my last period was on Oct 9 and it says it suppose to had started on the 6 Nov. I have not gotten my period. (3 days late). Im worried that I may be pregnant but I took a test yesterday it was negative. What should I do? I have had unprotected sex with my husband. Thanks!
You can get the most accurate result 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.
I had unprotected sexual intercourse on November 5 2015 on November 6 I came on my period. Is it possible I could be pregnant?
Hello, No, You cannot see your period while you are pregnant,the only thing that can happen is bleeding mistaken for a period.
Hi, my last period came October 14, had sex on october 18, 25, 28, 30 until November 3. I was supposed to have my period on November 8, but nothing happened and I just started feeling the symptoms. My cycle is for 28 days, and I’m a but worried because I’ve been really stressed for the past 3 weeks and I was wondering if that was the problem cause I never have irregular period, and sometimes my periods would come at the last week of the month
You ovulated from October 26 to 30, 2015 so it’s possible that you conceived. You tested too early. Take the test on week after you’ve missed your period for the best results. Your period could be late because you’re stressed or pregnant.
Hi, I have been getting periods mostly before 28 days say may be anytime between 23 to 28 days. Is that a cause of worry?
It may not be, irregular periods are normal. If the irregularity in your period also comes with excessive pain then you can consult a doctor at that time.
I had my period oct 7 then i had sex oct 24. until now i dont have my period . Is it possible to get pregnant? Am i pregnant?
My last period was Oct 11, which means my next one is supposed to be 8th Nov, had all the cramps and wiped just little blood and just sported a little too,then today 9th the period came out as it supposed to.now my question is, can I still count the 8th as my 1st day of this cycle or 9th. Thanks.
Count the 9th as the first day since that is when the actual bleeding started. The day you spotted should not be counted.
Hi I got my period on October 4th and I had sex unprotected sex on October 22nd my period was suppose to get here a week ago, my periods can vary between 27 or 29 so I’m not really sure when I ovulate, I took a pregnancy test this morning and it came out negative. Today will be the 37th day of my cycle and this never happened before. Could I be pregnant? Was there any chance to conceive on the day I had sex?
It is possible that you ovulate around October 15 to 21. Ovulation typically occurs 14 days before the start of your menstrual period. If your cycle lasts for 28 days, you can ovulate on the 14th day like the average female. The best time to take a pregnancy test is at least one week after missing a period. It could be that you tested too early. It is likely that you did not conceive this time. You can wait to see you’ll miss a period and take it from there.
Hi, I had my period on the 30th of September and ended on the 4th of October. Today is the 9th of November and I have not seen my period yet. I took a pregnancy test on the 4th of November but it came back negative… Should I wait a few more days and take another test??
Hi, Yes you should wait and take another because even with negative pregnancy tests you can still be pregnant.
my last period was 27/10/015,and I ‘ve been trying to conceive, could u pls let me know my most fertile days so I can be aware
Hi, If you have a regular 28 day cycle then Your next most fertile period is November 08, 2015 to November 12, 2015.
I had unprotected sex on 6th day of my periods i.e 18th of September 2015. I came in my periods again on 7th of October 2015. Generally my cycle is of 28 days but still I haven’t got my periods till today i.e 8th November 2015. Can I be pregnant?
Hello there, Lots of things can make you miss a period other pregnancy but if you had unprotected sex in october its possible you are pregnant.
Had my period on 15 September and 7th October…whats the expected date of my periods in November?
Hi my last period was on September 2 2015 and it is now November 7 2015. I’ve taking 3 test and all positive but last night had bright red spotting. Am I pregnant?
If the tests are positive then this means that you’re pregnant.
I started my period on 13 October and it ended on 18 October,then I had unprotected sex on 28 October but now I’m scared of being pregnant because I’m seeing some signs in my body like abdomen pain and breast pain.
You’re at risk of becoming pregnant if you had sex on or just before you ovulate. If you have a 28 days cycle then your chances of being pregnant would be high because you were ovulating from October 25 to 29 and you had sex on the 28th. Your November period was due on the 10th; if you miss your period then take a pregnancy test by November 18 to confirm if you’re pregnant.
My last menstruation was 4th of Oct, 2015 and another came on 6th of November, 2015. Before the recent menstruation, my mouth was tasting bad, belching every minute, unable to eat, But on 6th of November, I saw blood. What is wrong with me, am I pregnant or what is going on?
It seems you’re not pregnant. The symptoms you experienced seem to be linked to an upset stomach. If you have indigestion and an upset stomach you may need antacid to settle it.
I had my cycle on the first of Oct and it ended the 4th. My next cycle was supposed to start Nov 1st it is now the 7th and I still haven’t started. So I went and bought an hpt it showed negative what should I do I’m so lost.
To be sure take the test within two to three days time and be sure to do it as early as possible in the morning. If the test is still negative then, you may not be pregnant. It could be that your period is late for other reasons.
I’m in the same boat! Last DOP was Oct. 2nd, ended the 9th. Next cycle was supposed to begin Oct. 30th. Today is the 7th and no AF yet. Hope all works out for you in your favor! !