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





Hey, I have a problem. My last period started on the 22nd June and ended on the 27th June. Ever since that time I haven’t seen my period; my cycle normally takes 20 days. Am I pregnant or what? Today, the 21st, I saw blood and it’s painful. I don’t understand.
I have a 23 days cycle my last period was on july 7 I had sex july 17 is there a chance of me getting pregnant?
Hi Steffy, for more than 3 months my period comes on the exact day the 19th of each month. I had unprotected sex on the 4th of July and I have a cycle of 32 days. Up until today, I haven’t seen any sign of my period. Could I be pregnant?
It is possible that you’re pregnant. If your period does not come by tomorrow, you have to wait at least another week before you will be able to confirm if you are pregnant.
I had sex on the 21st of July though he didn’t release inside me because he used the withdrawal method. I’m to start my ovulation on the 27th or 28th of July. Please, can I still get pregnant?
Using the withdrawal method still puts you at risk because sperm can be released in his pre-ejaculation fluid. The chances are low – especially if he pulls out without spilling any of his semen. You may not be pregnant, but it’s always more accurate to wait and see if your period will be late.
Okay I’m trying to figure out when I’m going to be ovulating. My last period began on July 11 and ended on the 15th. I’m trying to conceive and need to know when I need to be having intercourse with my husband. My cycle usually is anywhere from 29-32 days. Please help me!
The online calculator via our link http://womanjunction.com/ can help you to determine when you’re ovulating. With a 29 days cycle, you are most fertile from July 24 to 28, 2015. With a 32 days cycle, you are most fertile period from July 27 to 31, 2015. Give it a try, it’s quite easy to use.
MY PERIOD WAS SUPPOSED TO START ON THE 21ST BUT NEVER ARRIVED. IM THINKING OK COOL MAYBE IM LATE. BUT I QUESTION THINGS THAT HAVE BEEN GOING ON FOR THE PAST ALMOST TWO WEEKS THAT ARE DIFF LIKE MY MOUTH SUDDENLY PRODUCING MORE SALIVA CAUSING ME TO FEEL SICK,WHICH NEVER HAPPENS UNLESS I’M SICK, HARDLY HAVING ANY CRAMPS , FEELING HOT A FLUSHED DURING THE DAY WITH A LOW GRADE FEVER THE RISES TO 99.1 FOR NO REASON BECAUSE I DON’T DO ANYTHING, BREASTS JUST STATED TO GET SORE LIKE TWO DAYS AGO BUT THEN AGAIN NOT REALLY, WAS FEELING SICK FOR OVER A WEEK BUT ONLY THREW UP ONCE, MY SKIN HAS BEEN SO ITCHY FROM HEAD TO TOE NEVER EXPERIENCED THAT AND I CANT SLEEP THROUGH THE NIGHT. THERE IS PROBABLY MORE BUT I CANT THINK OF IT. IDK IF ITS STRESS OR I’M PG. I USUALLY HAVE A 28 DAY CYCLE +-1 BUT THESE SIGNS ARE DIFF TO ME SO IM CONFUSED.
I started my period July 9th and had unprotected sex on the 18th. He pulled out with plenty of time to spare, but I’m still really scared. I have really irregular periods, sometimes up to 3 or 4 months in between, although lately it’s been about a month and a half. Is it very likely that I could get pregnant? I start college in September and all I can think about is that I basically just threw my future away.
My period was on June 30, 2015. I had sex on 18th of July. I am worried whether I will become pregnant. My period are normally 30 days. Kindly advise.
My period was on the 30th of June 2015. I had sex on the 18th of July. I am worried whether I will become pregnant. My periods are normally 30 days. Kindly advise. Thanks.
I was supposed to have my period on the 18th of July; still never got it. I’ve been having brown spotting since Thursday the 16th, but no actual period. I’ve taken a home pregnancy test and it was negative, I’m now 3 days late. Could I actually be pregnant?
It is possible that you’re not pregnant. Your period may be just be late. This post may help you http://womanjunction.com/what-if-your-period-is-late/
Hi, I got my period twice last month which was June 6 then it came on again June 21. It is now July and it came on the 17th it was not normal – it was thick and brown then it turned red but it was never really heavy. Is there a chance I could be pregnant?
Your chances of being pregnant depends on whether you had unprotected sex during your fertile period. This was not stated. Changes in your flow and cycle may be caused by many factors including stress and anxiety. This post will provide some useful insight http://womanjunction.com/menstrual-cycles-month/
I know you use your last period to see when your due date is. But what if you just spotted your last period would you still use that date?
Hi. I had my period last June 12 but I’m not sure though what is my cycle cause it’s not consistent every month. I had unprotected sex on June 22 and if I use a 28 days cycle then my fertility date would probably start on June 23. Now, I’m expecting to have my menstruation on July 17 but it’s still not coming. I’m a little worried. I already did a pregnancy test last Saturday July 18 but it’s negative but still I’m worried.
Having irregular periods makes it harder for your fertile days to be determined. This post on when to take a pregnancy test will provide some useful information, especially since your test was negative http://womanjunction.com/home-pregnancy-test/
My last period was June 21st-25th. I was supposed to get my next period July 17th, but it’s a no show. I am four days late. My breasts are not sore, I have slight cramps here and there, my sleep patterns have been off these past two days. My tummy feels different. I have two children already, so I know every pregnancy is different. So what could this be? Pregnancy?
I had my menses on the 24 of June and I had unprotected sex with my man on the 13th and 15th July. From the online menstrual calculation I’m most fertile on from July 4 to 8. Will I get pregnant?
If you have a regular cycle, your chances of getting pregnant would be very low.
I had sex on 17th of July midnight with my partner without a condom. Then I was my period on the June 24th to 28th. Is it possible for me to become pregnant or not?
You would ovulate on July 06 to 10 if you have a 28 days menstrual cycle. Your chances of being pregnant would be low unless your cycle is different.
do you mean that I’m pregnancy while period is about to started on 26th or not because when i calculate myself I will be on period on 26th
if i ovulate from 6th to 14th July than i had sex 17th in midnight is possible that I’m pregnancy or not?