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 period came on Oct 2 lasted 7 days. I was suppose to get my period on the 31 now its Nov 9th and i still haven’t gotten my period. I been having cramps on and off also discharging more and a little light headed, I haven’t take a hpt yet when should i take a test to get accurate result? please get back to me as soon as you can and could it be possible that i can be pregnant !!
Hi , it is more then time to do a test, result will be accurate as you are very late
Good luck
Hi
I still haven’t gotten my period and still haven’t done a test. Do you think im pregunt I really haven’t gotten early pregnancy symptoms. But not every women get them I have gotten on and off cramps discharge and been more tired and not much emery
Hi my last period began October 13th and on November 3&4th my boyfriend ejaculated inside me twice my periods are irregular so would there be a possible chance that I may get pregnant.
Hi, I had a monthly period last september 7 2014 and then october 2 suppose to be my period come again october 27-30 but its already nov. 4 still don’t have my period. I check two times one october 28 and last nov.3 I tried to check again I was negative… Am I pregnant or what???
Hi ,
skipping cycle is completely normal in a women life, with 2 negative tests, I guess you are pretty sure to not be pregnant. Changes such as new diet, gym , stress can lead you to change your cycle. If you skip another one , I recommend you to visit your physician for more answers.
Good luck
Hi,
m 27 yr old,i had one misscarriage on sep 21 recently and after words my mensural cycle came at 40 days.I had my period on 31 oct. is it possible to get pregnant soon after one miscarriage. I’m very tensed.
I had a miscarriage on September 15 th then had my first cycle after that on October 11th, I just found out that I’m pregnant again. So it is very possible. Good luck.
Hi, my LMP was September 27 to October 1. I had unprotected sex on October 4th 2014…….my period is now due from the 25 of october and I’m now six days late……I had two pregnancy test done both showed negative. I’m worried cause my period is almost a week late,what do you suggest I do in the mean time?????waiting a reply.
Hi , you had unprotected sex a way too early to your fertile window, but some women ovulate twice in a month … It is normal to skip a cycle along with changes in our life style such as diet gyr routine , stressful job
If you are uncomfortable or have question always feel free to visit your physician to get more answers !
Good luck
Hi, the first day of my last period was September 22 and ended on September 26. I had sex on September 27th, my period was due October 22th and it came on October 25 but my flow was extremely light compared to my normal flow and it lasted 4 days instead of 5. Could I be pregnant?
Hi ,
being pregnant on a single day of intercourse, 10 to 12 days before your fertile window is like winning to the loto … possible but extremely unlikely. Test yourself it is the only way to clear your mind. It is happening as well to have lighter flow … or even to skip a full cycle.
Good luck
I had my last period September 24th. I should have started last Friday Oct 24th as I’m always 30days… FOR 2 Weeks & today I have had cramps on and off (Usually only happens 1 week before period). My stomach feels tight & achy.(at night when I lay on my side also) I also have been pooping a a lot T.M.I Not sure if that’s related. I was really wet this week I should have started. Every time I felt like I was getting my period it was just wet. I have been with the same guy for 3 years now & we have been trying/not trying on and off. I’m nervous about testing because its always negative.. but I feel my weird & my period is almost 1 week late. Any Ideas???
Hi dear !
Test yourself ! If it is negative, visit your physician… it can hide something else that need to be looked at…
Good luck
My cycle came October 7-9 which was odd bc i have a 5 day cycle & its never irregular. My bf & i dont use protection but he pulls out everytime. We had sex on the 10,11,12,19,25,&26 of this month. Yesterday a.m. i used the bathroom & saw blood when i wiped but that was it, and same thing happened this a.m. What can be going on?
Hi,
First, let me inform you that the pulling out method is not a contraceptive method as it is only 74% reliable… against 99.99 for condoms. Being irregular from time to time can happen in a women life for many reason such as stress new life style or new gym routine. You should test yourself for a possible pregnancy. If you are not comfortable with your symptom, a visit to your physician is always a good option also
Good luck
Hi, my period came on Sept 25th lasted 7 days then 3 days later i had light spotting for 4 days then it stop. Since after i have been experiencing pregnancy-like symptoms. So what I was wondering is, is it possible to have a period and still implant onward…. just curious????
Hi,
it is quite possible, as some women experience period like bleeding during the first trimester … the only way to figure out is to test yourself ! Spotting is not unusual as well from time to time !
Good luck !
hey i got my period on october 8th what are the ovulating days and fertile days ?
hi,
october 8 th will be the day 1 of your cycle, so your fertile window is between day 10 to 17 depending of the lengh of your cycle. so from the 18 th to the 25 th for this month.
Good luck
Hi I had my last period September 5 then it came back on September 29 when should i expect my cycle for November
Hi ,
well, it depends if you have a regular or irregular cycle… if you do, it will be a 24 days one … if you don’t , there is no way to know when it will start. If being irregular is something making you uncomfortable, visit your physician to discuss about that there is solution to help you to have a 28 days regular cycle.
Good luck
Did you find out why
hi..my last period was september 27, and i had sex, third week of october(oct.12-oct.18),,is there a chance that i get pregnant?thanks.
Hi !
Yes there is chances that you might been conceiving within theses dates !
Good luck !
With pre cum can I get pregnant while ovulating?
The first day of my last period was the 23rd of September
It was heavy for three days then barely existant for the other
two . Am I pregnant I have taken two test , one showing a faded line and
one clear after an hour ! Help !! I am currently trying to conceive !!
Hi, 3 days of heavy bleeding is clearly periods or a miscarriage … I doubt that you are or still are pregnant. Tests are more effective with the morning urine as it is the one having the highest concentration of HCG, the pregnancy hormone. the result have to show within 5 minutes .. past that it is invalid. Test it again !
If you have doubt, visit your physician that will be able to give you some clear answers.
Good luck
I had my last period on September 31. I usually get my periods earlier dan 28 days.. I had my inteecourse from 10th oct to 18th oct except on 13th and 16th.. I am planning for my baby.. are there any chances for my pregnancy and when could be the best time to test?? Can u pls suggest me on this..
Hi , everything is possible ! test yourself as doom you are late for your next period or as soon you reach 14 days after an unprotected intercourse. To conceive it is always better to have sex one day on 2 while being in your fertile window. it allows more mature spermatozoids to be launched !
Good luck !
I menstruated on the 22 or 23 of july 2014 then in august i realized that I am pregnant.
I had sex on the 3rd of July and again around 6 and 9 Jusly then I went to the Dr on the 13th of October 2014 he said am 12weeks 4days so now I wanna know when exactly did I got pregnant …3rd July or the sex I did around 6 and 9 July?
Hi strange as it can shows, the day one of a pregnancy is the day one of the last period you had, they calculate from there 40 weeks of gestation which give 10 months … knowing that basically your fertile window was 10 days after the beginning of your last periods, that lead you to track the possible conception dates ! and redude at 9 month and a half the pregnancy !
Good luck
My period started Sept 26th and I had unprotected sex Oct 9th and 11th, 3 days later I started to feel light headed, my breastfeeding hurting and using the we way too often could this mean I am pregnant? Did 3 pregnancy test and all negative help help
Hi ,
it is taking much more then 3 days to have pregnant symptoms, if it was so quick pregnancy test will trigger much faster too… it takes 14 days after an unprotected intercourse to trigger a positive test. Look to your date and test yourself accordingly or wait to b late on your next period, if you have a regular cycle. Test yourself with the morning urine. With more HCG you have more change to have an accurate result.
Good luck