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 I haven’t took any birth control IN a year now but finding it hard to get pregnant my period was on January 24th was supposed to start Feb 16th still haven’t
last month I got my period January 13 lasted 4-5 days, I have regular periods and I should have my period by now but not. I’ve done 2 test already all negative, is it too early to test? I have some symptoms like breast tenderness but it happens to me also before i have my period. Should I go consult a doctor ?
Hi, do you have any reason to wonder if you are pregnant ? Are you taking any birth control method ? Did you just change job or started a new work out ? Stress is very powerfull and can delay period, even skip them completely. If you have no reason to believe that you might be pregnant, I would let this cycle pass and see if the next one is coming. By now if you were pregnant a pee on a stick test will be accurate.
Good luck
I got my period on jan 16 it is February 17th why am I late I don’t think I’m pregnant but just wondering why… I’m not stressed or taking meds
You can find some answers in this post
had my menses on the feb 25 and ended on feb 29. i had unprotected sex on the 4,5,6 feb but I used the withdrawal method. I took an emergency pill on the feb 5. will i get pregnant?
Hi, first of all, withdrawal method is not a contraceptive method it is playing russian roulette … if you don’t want to conceive please visit your physician for a reliable option. Taking the emergency birth control pill was a very good move from you, the pill in fact trigger your periods by simulating the hormonal peak you have when the time come for the unconceived egg to be ex-pulsed with the endometrial tissue. Which is preventing a conceived egg to attach to the endometrial tissue at this particular moment. As you know this pill is effective within a thin range of 72h after the “incident “; earlier you take it better are your chances to meet your goal of preventing a pregnancy.
Good luck
my first day of menstration is on jan. 30 until feb. 2. then i and my husband had sex this feb 17. is it possible that i get pregnant? i dont want to be pregnant anymore i have 3 kids there ages are 6, 4, 2. thanks for the answers..
Hi,
not to be judgmental, but if your family is done, you should discuss a reliable contraception option with your physician, instead of hoping the nature will not start you up again. As well , if you have a regular cycle, the 17 th was into your fertile window big time.
I had my period on January 17 (which was a Saturday and got off January 23. I had sex January 25, 27,”twice on” 29, 31 and continue to February 2, 3, 4, 6, 9, 11 all were unprotected. I was suppose to start my period February 14 (Saturday) but it came Sunday night at 10:40p.m …I wanted to be pregnant but it looks like my egg died.
Hi, getting pregnant is a little bit more complicated than that, some will try for months or years before succeeding. Eggs don’t die … they get fertilized or they don’t and get ex-pulsed with the next period with the unused endometrial tissue.
The best way to increase your chances to conceive is to have intercourse only one day on 2 of your fertile window, to allow more mature spermatozoids to be released. Too much is like not enough.
Good luck
First day of my period was January 15- cycle 28 days and period usually about 5-6 days . I taken two pregnancy tests both negative.
i last had sex on feb 14th & my period came in feb on the 23rd. Could I be pregnant?
My last period started on January 19, 2015 and my new cycle has not started to date. we had sex @ Feb 02, 2015 actually not a real sex just touching but I’m afraid and is that a danger time to be a pregnant pls i need fast answer I’m so so worried
I’m 42 years old my last period was January 17,2017. When is my next period?
Hello there Gina, you did not say how long the last period lasted, however, the next period should be around 4/5 weeks after January 17th.
My last period was on the 17th of january and the app said my next period should be on 14th february but did not come. I had sex on 5th and 13th of this month. Usually have tender breast a week to my period which i felt this week, rite now my nipples hurt. Could i be pregnant and can i test now?
Hi, a menstrual calendar works for regular cycle. Are you regular ? if not … well it does not work as … being irregular is .. having a random cycle. Sometimes we also listen to much to our body and trigger symptoms that does not exist, this is happening especially to women trying to conceive and listening to any possible sign of pregnancy … this is just normal ! If you think that you are late, test yourself ! You had sex late on schedule, but often time, life is finding its own way !
My last period was January 3rd and I still haven’t got my period. I took a pregnancy test but it came back positive… I’m not sure could I be pregnant? I’m very normal with my periods.
Hi, some medication will trigger false positive test. Discuss this issue with your pharmacist if you are taking regular medication. Visit your physician if you haven’t, a blood screening does not lie !
My last period started on January 8th and lasted 2-3 days. my new cycle has not started to date. I did 2 home pregnancy test first urine of the morning on February 4th and 5th and they both had faint positives. I don’t have any pregnancy symptoms. Am I pregnant? I don’t want to get all excited to be then disappointed.
yup
Hi ,
fainted positive is a positive still, but pay attention, some medication can trigger a positive test. If you are taking any medication please see with your pharmacist if they can interfere with your pee on a stick test. The test should reveal darker more the days will pass if you take it again as the HCG level can only increase if you are pregnant.
Good luck
Hi, I came on my period Jan 15th and came back on feb 3rd for about 3/4 days. I usually come on around the same time each month , the month is almost up and I don’t have symptoms of it coming . I am hoping for pregnancy but I’m not quite sure could I be ?
Hi there Miracle, the only way to really confirm if you are pregnant is to take a pregnancy which I would advise in a case like yours. All the best.
My last period was January 10 and lasted for about 6 days which was odd because my period usually only last for 3, I had a bunch of unprotected sex throughout the whole month of January. This said my period was due on the 8th my app said the 9th and well today is the 10th and still no aunt flow. No symptoms. Could I be pregnant?
Hi , the odds that are are pregnant are very low as you got period, even they were heavier than normally, that could lead to believe that you might had miscarried, as most of the miscarriage will occur in the first 4 weeks even before the lady learned about the pregnancy and will cause heavier bleeding … when the period is triggering. Which is nothing to be sad about, because if it is happening so early it is because the embryo was not viable. If you are trying to conceive, keep going ! If you ar enot I recommend you to discuss birth control with your physician, if you have a steady partner with who you want to have unprotected sex.
Hi, I had my period on 5th February so when can I get it again?
Hi there Rosemond, a normal cycle can last anywhere between 28-31 days. All the best.
I last had sex on January23 & my period came in January on the 11. It is now February 8th & my period hasn’t came & I have no signs of starting. Could I be pregnant?
yes you might dear
I last had sex on December 20th & my period came in January on the 2nd. It is now February 5th & my period hasn’t came & I have no signs of starting. Could I be pregnant?
no..!!!
Hi , odds are very minimal but some women will have period like bleeding in their first trimester, there is only one way to clear this out ! test yourself ! At this point test cannot lie!
Good luck
My last menstrual cycle ended on the 31st of December it is now the 5th of February and I have not had my cycle yet. Is it to early to take a pregnancy test?
Go for pregnancy test. all the best.
you didn’t mention how long your cycle usually last, but nevertheless I’d say that it’s not too early to take the test. good luck
My cycle usually lasts 5 days. I took a test on the 6th (negative results) still no sign of my cycle.
Nope, you can get more accurate results if you take a test the first time you pee in the morning.
i think you might be expecting…