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 was intimate with a guy in April but no sexual intercourse, saw my period that month and next which is always last week of a month/ 1st week of the next month. But june/july I experience more like spotting and period cause it stained my underwear and it lasted for 5 days. And its 12 days after and I feel I’m ovulating. Could that be my period or what? Pls I need a reply. So confused
hey, yes, that could be your period, especially if you had more mental or physical stress in the last 40 days which may impact your cycle. if you, as you say, didn’t have a sexual intercourse then there’s no possibility of pregnancy.
consult with your physician if you’re worried that there’s something wrong
Yea I experienced mental and physical stress which I’m still experiencing fear and ansiety at d moment. But is it possible for another period to show up 2wks after that?
it is quite possible too, that you had a multiple ovulation month ! some women have a ovulation on demand mode, being in love, new relationship can made changes in your hormonal balance. If you can live with it ive you 2 more month to see if it will stabilise if not , you can always discuss about your concern with your physician
Good luck !
I had 2 periods in one month of june the beging and the end. june 28 is when I started again but didn’t know and me and my boyfriend had unprotected sex and im worried I might be pregnant
Hi , getting pregnant while having period is rare but not impossible, it depends if you had an ovulation or not, personally I already got pregnant on my late period and I was explained back then that some women have what they call … ovulation on demand. Meaning that the only desire of conceiving can trigger an ovulation. If you are regular, make sure your period arrives on time, if not do a test.
Good Luck
Had my last period the 2 June 2014 when is my next cycle date in July?
Hi , the date of your next period will depend of the normal length of your personal cycle as it is different from one women to another. Normally it should be 28 to 30 days from the first day or your period to the first day of the next one.
Good luck
Hi, i had sex on 13 july and the first day of my period was 2 july and lasted for 5 days, i have a regular cycle 25days am i safe?
Hi ,
Not safe, you ended being at the beginning of your fertility window. Protect yourself if you dont want to conceive at all time. As some women have more that 1 ovulation per cycle.
good luck
Hi my cycle was on may 26-30 I and my bf had sex on the 31st and I am now pregnant ..but I am not sure how far long cause I don’t know how this works
Help
Hi ,
the best way to know will be to do a blood screening, by the level of HCG, your doctor will be able to tell you how many weeks are done so far. That will indicate you as well if the latest may period were real or if you were already pregnant before … by now even if they were real, you will have an heartbeat audible at the echogram.
good luck
Hi I’m Linda,I saw my last period on the 24 of November,and my period lasted 5 days. I met my boyfriend on the 1st of December and 2nd,please now I’m pregnant,is my boyfriend responsible for the pregnancy because I’m confused.
hi Linda. I presume you took a pregnancy test and it turned out positive? Is your boyfriend the only person that you had sex with? if yes then obviously he’s the father. if not, a paternity test will clear up the doubt. good luck
Hi I saw my last period on the 6 to 9 June and I had sex with my boyfriend on the 10th. the period it usually 28 days am expecting it on the 3 July. But til now nothing, does it mean am pregnant. Pls I need ur advise
Hi, unless you have a double ovulation, you were still far from your fertility window. Conception stress is enough to relay your period. Do a test, clear your mind ! if the pee on a stick test turns negative and you still have doubt dont forge that a blood screening is not lying
good luck
Mine is regular but even when i meet my hubby while ovulating nothing happen.though i hv a 3yrs old daughter.tanks
Having the same problem here too, cos I have 3 years old son, so what is the way out dea
Could this be a sign of a problem?
having both of you a 3 years old child on not the sign that you both have difficulty to conceive for the same reason. It is a pure coincidence. If I can give you a tip that will help you conceiving is that once you will first accept to let the nature go and stop putting you the conceiving stress on the shoulders, have intimacy only every second day during your fertility window which is normally day 10 to 18 of your cycle, day 1 being the first day of your period.
good luck
Hi ,
I have irregular periods.
Periods came on Apr 29, the next one on june 07.
I am trying to get pregnant .
can you tell me when will i be fertile next .
I took ovulation test at home , came negative
hi, with irregular cycle it is very hard even for the test to help you out. The general rule is starting from your periods day one, count to be more than sure 12 days , then have intercourse every 48h, not more, to allow as much mature spermatozoids to be sent… they live 72h in the womb so there will be always some ready for your ovulation to come, continue this routine until your next periods, normally we can stop day 21 .. but with irregular cycle it is a little bit more touchy! Relax don’t think about conceiving … I know the pressure is hard. But to have to let the nature do its voodoo magic !! enjoy the moment you have with your partner, and don’t think about the conceiving performance. A lot of couple that struggle to conceive finally achieving it when they quiet the project ….
good luck
Hi I am tricia ,I gave birth on the 26th May 2013 and my menses started this year 09th June 2014 bt it did not flow as my normal 6-7 days it came for only three days and i want to know if this is normal. . I also want to know when my next menses will come.
Hi , you will need a few cycle to determine if you are regular or not after your pregnancy. As it could rumble a lot of thing in your cycle. Good luck !
hi my last period was 19 of may to 22 of my and i had an intercourse with my hubby but till now which is 27 of June have not seen my period does it mean I am pregnant?
Hi i saw my last period on the 14th of may -18th, and this month june I have not seen my period. I didn’t have any sexual intercourse, pls am worried
Its been 45 days since my last period and the only pregnancy symptoms I have are mood swings, bumps on my breasts, and being fatigued. I took several hpt and they all came back negative I dont know whats wrong with me?!
Hi,
being pregnant is not the only reason to skip a cycle. Starting birth control pill, new gym routine , stress lack of sleep and conceiving stress can also delay or completely skip a period cycle.At this point if you are listening too much to your body you might trigger these pregnant like symptoms If so far the pee on a stick test is giving you negative result and that you still have doubt, do a blood screening.
Hi.i and my bf had sex during my first and second day of my period.its posible to get pregnant. Im so worried!!please help me!!
Rare are the case of the lady getting pregnant during their period but it is possible, if by example you have a second ovulation from your other ovary 2 weeks after the initial one. I got pregnant that way for my second child on day 4 of my period…. I am a living proof that it can happen. The nurse explained back then that some women have what they call ovulation on demand. The desire of conception is enough to trigger more ovulations.
I been on depo for 2years n since I been on depo this the first time it ever came on like this my period been on for a month now but it come on in it go off but last night I had sex with my boy friend in my period wasn’t on then but I go get my shot next month n I wanna know could I be pregnant….can y’all please give me a answers
You must take a pregnancy test before you take your next depo shot. If possible let your doctor examine you as well.
The chance of you getting pregnant is narrow.
My last period was may 14 2014 I had sex may 25th and I havent had a period this month I always have 28 day cycles
I had sex may 21,14 my period is suppose to come 6/2/14 im a week late ive been bloated, emotional, constipated, lower back and stomach cramos and had 2 negative hpt. Should I test again or take it as im not pregnant
Sometime listening to our body trigger some symptoms, but you had sex into your fertile window. Test it once again, if you use a pee on a stick test, use the morning urine the concentration of HCG will be at his most concentrated and the test will not lie !
good luck
Thanks I went to the er with bad sharp stomach pains told him my symptoms I listed above and he told me what I already knew all labs came back normal not pregnant but he say im sort of backed up! So he gave me a miralax still no period Iim 12 days late if af dont come im going to my clinic and see if they can give me medication to bring back my regular periods
I hope everything will be fine, good luck