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 jan.25,2016-jan.31,2016,,i have unprotected sex feb.12,2016 is it posible that am pregnant now?i ddnt have my period this month of feb..
thanks
There is always a possibility of pregnancy when you have unprotected sex. You can take a test one week after your missed period if you do miss.
My friend had her period on the 7 of febuary and it stop the 12 and she had unprotected sex the 14 can she be pregnant or how long show she wait b4 she can take a pregnancy text
Hello there Trudy, she should be able to take a pregnancy test in the next two weeks which will indicate the possibility of being pregnant or not.
So, I had my period on January 15th and then during sexual intercourse on Jan 26th, I had a good bit of blood that came out of me during the intercourse. It went away and then on January 29th/30th my period seemed to start again. Do you know why this would have happened and when I should expect my next menstrual cycle. I’m totally confused and even more confusing is trying to find out when I am fertile as we are trying to have a baby.
Sometimes minimal bleeding is normal, it is a shift in cycles. Tracking your periods can truly help with this.
my gf has started her monthly period on 14 feb., and we got sex unprotected on 14, 15, 16 and 21 feb. 2016 and she take pill this day only its possible she got pregnant?
If you have unprotected sex you can get pregnant.
Hello,I had my last period on the 5/02/16 which lasted for for day…5,6,7,8.I had unprotected sex with my boyfriend on 25/02/16 can I conceive??? Please help.
I think you have a relatively high chance. Good Luck!
The first day of my last period was the 5th of January it stopped on the 11th I think..had sex on the 14th of February the 17th and 18th what are the chances of me being pregnant!
It depends if it is unprotected or not. I wouldn’t be too worried.
Hi my last period is January 16 ,2016 yesterday I have tried the pregnancy test February 24,2016 but it is negative. .Iam not pregnant. What’s the reason my period is not coming?
I’m going through the same thing
Hi,
My first day of my last period was the 28th jan, i had unprotected sex with my BF on the 2nd of feb, I have my next period on 25th feb (28day cycle) do you think i could be pregnant whether or not i come on my period?
You can get pregnant whenever you have unprotected sex.
Hi my period came on July 26 2015 I had sex a day before that and I had sex right after my
Period went off for at least 3 weeks straight and I am pregnant.. Which one could of led to my pregnancy?
Any could have, since they were unprotected. Most likely, it is the one after.
I had my period last on January 21 it stoped on the 26 and I had a romance with my boyfriend early January… but we didn’t have sex..today it’s 24 and I haven’t seen my period although I’ve got signs of it showing but it haven’t can I be pregnant?
Honey use your common sense…if you didn’t have intercourse…obviously you’re not pregnant
Hi I’m Donna I had my period on the 26th Jan till 29th we had sex every other day till now. I know I ovulated on the 12th Feb, I should get my period on the 26th Feb but all my symptoms are different to my pms I just feel different. could I have gotten preg x
Hi I had a period on January 23 my cycle is 28 days… Have had sex several times with my fiance…am I pregnant or do I need to wait a little longer?
Hi Chubbs. There is always a chance of pregnancy when having unprotected sex. According to the information you provided, your most fertile days would have been Feb 3-8. Best of luck to you.
Hi, I was on clomid and was given the 2,4,5,7 of February to have sex with my husband as we are trying to conceive. On the 18th of February I had some bleeding, not so much though and it lasted for 3 days. I was supposed to get my menses somewhere from 24th since I have irregular periods. Can I be pregnant ? What is happening to me? Please help explain
Hi there. Pregnancy is always a possibility. Are you sure the bleeding was not your period? Since your periods are irregular, it showing on the 18th would not be impossible. If you think you may be pregnant you can take a pregnancy test or see your doctor. Wishing you well.
I use to have a 26days cycle and I started my last menstruation on the 21st of Jan and wanted to know my ovulation period on the 15th day after several days of testing with my prediction kit got a smile on my clearblue I.e LH detected. I had sex with my husband that night and even before then have always been having sex with his so I won’t miss my ovulation period at the end of the month I was negative and my menstruation was delayed for 2days now in February I had a 28th days cycle when am I likely to ovulate. Along side my prediction kit am using folic acid +B12 all to boost my pregnancy. Please can someone should advise me
Hello there. According to the information you provided you are most likely to ovulate between March 5 and 10. I would suggest that you continue to do what you’re doing to keep track of your ovulation along with consulting your doctor. Best of luck to you!
I had my last period on 29 december 2015 and had sex on 23 january .i have missed my january period and had taken 4 urine test all negative. please advise as my february period also has not come yet
hi! my last menstrual period is january 20, 2016. I’ve tried the pregnancy test yesterday February 21, 2016 and it is negative. Does it mean I am not pregnant? thanks
There are numerous reasons why a period could be delayed, check our FAQ for more information.
Hi my last period came on the 28th of January on the 9th of February I had unprotected sex my periods are regular but today (February 21) I staterd bleeding later on durnung the day my period is suppose to start on the 25th of Febuary which makes today 4 days early to be starting why us it early?
It is a normal change of cycle, nothing to worry about!
Hi I’ve been having irregular periods sometimes I get them some times I don’t . I started my period February 24th and I should be done by the 28th or 29th . also I don’t understand how the menstraul cycle works and when do I ovulate. I also have been trying to get pregnant but for some how I can’t . my irregular period started almost 2 years now I believe so and its weird I mean there’s times I start it the first week of the month or in the middle of the month or just the end of the month . How can I stop that from happening? I was never like that before .. Please P.M . Thanks