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





Sarah
My period did not come on September but came on October 2nd. When should I take a pregnancy test.
Hello Sarah. I may need more details to answer your question.
I did an implantation that lasted only 3 weeks and was pulled out because of pores. After that I did not see my flow not until the 3rd of September. On the 3rd of October, I had an unprotected sex, Am I going to be pregnant?
Once the implant is removed, you can get pregnant as soon as possible. So if you had unprotected sex on Oct. 3, there is a possibility you got pregnant. You can wait for a few more weeks and get tested to confirm
Hi, I saw my last period on the 3rd September 2020 and I had unprotected sex on the 13th of September. Would i get pregnant? When is my next period date with my ovulation date please? 🙏
Hello Ruth! How long does your menstrual cycle last? If your cycle lasts for 28 days, your next period date is expected to come on October 1-3 and your next ovulation date is around Oct. 11-15.
Hi i had my period on Sept. 7 and ended on the 9th. I had sex on the 12th of September and I am yet to see my period on October 1. Pls can i be pregnant?
Hello Es! Your period is expected to come on October 5-7. If in any case you are delayed for a few more weeks, you can get tested to confirm your pregnancy.
Had my period on 31st of August and have not seen it to date. Is there any chance of being pregnant?
Hello Angy! I believe I would be needing more information to answer your question. How long does your menstrual cycle last? When did you have an unprotected sex? Delayed period could be also cause by other external factors such as stress, lifestyle and other things including pregnancy.
Hi I am a nursing mother I put to bed six months ago and I am on exclusive breastfeeding. I gave birth in March and my period returned on July 10th and I had a cycle of 32 days from July to August which normally I usually have cycles of 29 to 30 days. So I have had my period in July and also in August but for Sept it’s yet to come I have used pregnancy test strips and negative results have been popping up. Please I’ll like to know why my period hasn’t showed up yet. Is it because I am breast feeding is it supposed to cease once it has returned after childbirth? Thank you please I await your response.
Hello Taylor!
Congratulations on your bundle of joy! You don’t have to worry. It is normal for periods to stop especially if you are breastfeeding. On some instances, breastfeeding moms don’t get their periods for months and in your case, you had your period after 4 months. The hormones that produces milk also stops ovulation causing the irregular periods during your lactating phase.
I had my first sex on 28th of May and I was supposed to see my period on the 3rd of June. But I saw it on 30th of may which lasted for about 7 days and my menstrual cycle changed to 24 days from 27/28days. So, I saw my period in June and July but my menstrual cycle came back to 27 in August and I noticed that the previous 3 months menstrual bleeding didn’t flow like it used to and now in September it’s already the 27th day of my menstrual cycle but I’m yet to see my period. Can I be pregnant??
Hello Shuck!
It seems that you are having an irregular period that is why your menstrual cycle changes from time to time. It could be caused by different factors such as stress and I suggest you visit your doctor to know what could possibly be the reason for this.
Hi pls. I had my last period on July 31 and it ended August 3. I had sex on August 28 but it’s already September 2 and I haven’t seen my period. Could I be pregnant?
Hello Diva! Given your last month’s menstruation, it is possible that your period is just delayed. It could be due to a lot of factors. You could wait for a couple more weeks and if your period hasn’t come yet, you can do a pregnancy test to confirm.
I got my period on 16 July and it lasted until 20 July. Then i started again on 25 July until 29 July. I have not had a period since then. I am not sure whats happening
Hello Zozo! Does this happen on a regular basis? It looks like you are having irregularity on your menstruation. I suggest you consult your doctor regarding this matter as early as now.
I had sex a day before my period which is 4th feb2020 when cld I have concieved cz I missed my march periods and am now in the 6th month of pregnancy?
Hello Donah! Your possible conception date is Feb. 10 – 25. I hope this helps.
Hello,my last period was on 30th June and on 22nd July I had unprotected sex. So far have not received my menses and yesterday I made an attempt to test by not satisfied with the results.
Hello Doreen!
How long is your menstrual cycle? Is it regular? If it is, you can expect your period to come around July 28-Aug 1. You can then test again if it is still late.
My last period was 30th of May and I waited for my period June but didn’t see it till July 4th it came out and I am still breastfeeding. please what is my menstrual cycle because before giving birth to my first baby my menstrual cycle was 28 days but now am confused because sometime is comes 28,30,32. Please help me so I will know my faith. thanks
Hello Faith!
If you are still breastfeeding, it is expected to have irregular periods and your menstruation cycle could be longer than usual or even shorter. Don’t worry because once you reduce the amount of time in breastfeeding, your cycle should return to 28 days.
I had sex June 3rd and saw my period June 10 and didn’t have sex, felt sick and vomiting June 23 and saw my period. not sure if it’s period on 26th of June or is it likely I am pregnant
Hello Bimbo!
If you have a regular period, June 3 should be safe to have unprotected sex because you are out of the fertile window and you had your period on the 10th. The blood on the 26th could be spotting caused by a harmless hormonal imbalance. However, it is best to consult your doctor if you are still feeling sick.
Last period was may 28 had unprotected sex on 31 may please when is my period in june
Hello Jane! If you have a regular 28-day menstrual cycle, you should get your period by June 25.
How would I know if I’m having irregular periods or missed period?
Hello Janika, A normal menstrual cycle lasts 28 days, plus or minus seven days. Menstrual bleeding is considered irregular if it occurs more frequently than every 21 days or lasts longer than 8 days. Missed, early, or late periods are also considered signs of an irregular cycle. You need to track your period for 3 months, and if it persists you need to visit a doctor.
Hi my last period was on the 11th of April and it lasted for 4 days…on the 20th of same moth had unprotected sex…usually my cycle is irregular ….now its the 10th of May still no sign or symptoms of period or pregnancy. I’m worried cause I’m late for my next period
Hello Poshy, I recommend that you do a pregnancy test but there can be lot of reasons for a missed period or late period like stress, weight fluctuations, exercising too much, etc.