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





i had sex with my gf during the first of her period. Is it possible that she may be pregnant or not.
If it was unprotected, then you run the risk of pregnancy.
I had sex on the 30th of Jan and saw my period on the 14th of Feb after my Period of 5days I feel cramping in my leg and stomach those it mean am pregnant
You had your period so no, you are not pregnant.
what does it mean if I had my period January 1st then again the 29 but nothing for the month of February? was the one on the 29th for February ?
Hi Keke, On basis of 1st Jan and 29th Jan, your period cycle will be of 28 days, so you should have had your next period on 26th Feb. But, not everybody has a consistent number of days in the period cycle and there may be many reasons of missing periods. So wait a few more days.
I saw my period january 7 and saw the next one 10 of february this month…i had unprotected sex yesterday and today..is there any chance of getting pregnant..and when is my ovulation..i really need your help…I’m confused about this..
Hey Sanou, you always run the risk of pregnancy when you have unprotected sex. Your ovulation is around the 22nd-24th.
My last period was on January 29th 2016 ,Me and my boyfriend had unprotected on February 4th 2016 . it was my first time I haven’t took any birth control pills . My period was due today which is February 20th but didn’t come on and lately i been experiencing stomach pains ,spotting &dehydration .
Is this a early sign of pregnancy ?
This is too soon for me to know. Wait it out for a few more days, and if it still doesn’t show take a pregnancy test on the 28th.
Hi my period came on the feb14 and went off feb 17 which was weird i normally have a period for 6days but why did my period ended so soon
I cannot know for sure, I would talk to a doctor.
Hello my name is Tina I’m 17 and I’m stuck with the thought of being pregnant I had sex with my significant other a couple times before my period last month which is on the 17 and it’s now Feb. 20th I’m a week late , what should I do I really need help any suggestions?
Stay calm, because being stressed and anxious can actually delay your period. If I am reading this right, and you had it before your period last month, then I HIGHLY doubt you are prengnant. Just try to remain calm, and track your cycle.
My last period was on January 26 2016, i had unprotected sex on February 9th 2016 could there be a chance of me being pregnant?
There is always a chance of pregnancy when you have unprotected sex.
I have a regular 26days cycle but I was few days late. Thinking I could be pregnant. I had sex and to my worse nightmare. My period came the next day. Now my question is could I still be pregnant or could the sex have led to me getting my period?
You could still be pregnant, but the chances are extremely small.
My bf and I had sex on 23rd of january 2016 then 28 – 30 january. We had unprotected sex again on 1st, 3rd and 8th then 14 feb. after sex I had very light bleeding. Next day again I got light spotting and I felt very horny that day so I had sex with my bf. Does that mean I got pregnant?
Hi Vane, There is no way to calculate the possibility of pregnancy without knowing the actual start date of your period. There is always a chance of pregnancy when having unprotected sex. You should take a pregnancy test and see a doctor for further investigation. Best wishes!
i had my last period on the 23rd january, and had unprotected sex a week after and exactly 17days after my period i saw blood spotting in pinkish color and later chocolate brown and it stopped after 2-3 days of spotting. am i likely to be pregnant?
If you had your period, then no you are not pregnant.
My mom had what appeared to be a regular cycle until she was 4 months pregnant with me. It isn’t likely, but IS a possibility. Also, what was described sounds similar to the spotting I had with my son. If this hasn’t been resolved already, definitely try a home pregnancy test after the first day of your missed period, assuming you miss it.
My last period started on the 10th of Jan I had unprotected sex on the 27th of Jan was due for my period on the 13th of Feb and haven’t got it. took a test on the 16th of feb. Would there be a chance I am pregnant and should I do another test considering I have missed my period?
Hi Janet, If you had unprotected sex and have missed a period, there is a chance of pregnancy. Take another test. Are your periods ever irregular? If your test is still negative and your period does not show up, you should call your doctor. Good Luck!
hi, my last period was on the 30th Jan till the 5th, nd I had unprotected sex on the 6th but he didn’t penetrate inside .could I be pregnant cause i feel dizzy with light headache and also a running stomach
Hi. My wife and i have been married for 11 months now and have been having difficulties in conceiving.
She doesn’t experience any of the ovulation signs listed,but few days before her period arrives few pimples appear on her face.
Could it be that she doesn’t ovulate?
Also her cycles are not always regular. Its sometimes 23,25,27,28. What could be wrong with her? She is above 35 years. Thank you.
Hi there. If she is having a period she is ovulating. Her age factor and irregular periods may make it difficult to pinpoint the time of ovulation. Has she seen a doctor? The only way to be sure of any problems would be to see a doctor. Wish you well.
Hi am so worry and I need help…
I was doing dry humping with my partner and I was fully dressed but he was naked so I don’t know if there is anything entered in me. I missed my period on Jan and I saw it Feb 9 the first 2 days was heavy, the 3rd day was little bit and the 4 day nothing has come. then 5 day it come again but am still worried could there be any chance of pregnancy. please help me
if you had your clothes on and got your period afterwards then there’s really nothing to worry about. the period might be late due to stress or some other factor
I saw my period on the 29th of December and I was thinking I was pregnant till I saw a little blood on 31st. For the days without a heavy flow. But on the 2nd of February a little more than the 31 and 1. And it stopped on the 7th of February, not heavy flow like before. Now which date should I check? I had sex with my man from 9 10 11 12 13 14 15 16 is it possible for me to get pregnant?
Hi Fav, Pregnancy is always a possibility when having unprotected sex. Because your period was irregular it is a little hard to pinpoint your most fertile days. Good Luck to you!
My first day of my last period were on 16 Jan 2016 till 22 Jan and I’m have sex with my husband on the last day on 22 Jan, but he wear a condom for protect ion. but until now on this day my period haven’t came yet ? are there any problems?
hi, your period might be late due to any of these factors