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





Thanks for the help
after i had sex with my husband on my ovulation period, i saw my menses some weeks later but it didn’t flow too well like before till now i have not seen my ovulation period is almost 20 days after my menses
I would see a doctor about this. While I am sure that you could google it or someone on here could giver you possible answers, the only way to know fore sure what is going is is by going to the doctor!
I had my son on April 8,2015 an I still haven’t got my period back as yet,could I be pregnant again???
The only real way to know if you are pregnant is to take a test or get a test done by a doctor. However, it is possible to get pregnant after giving birth, as you can ovulate as early as 25 days post birth. I would take a home test if you still have not gotten your period, and then go to a doctor if you are not to see what is going on.
my period date was 5 th june..and i had intercourse on 16th june..usually i get in period 4-5 days earlier then my date..so what are the chances of pregnancy?
According to your dates, your chances of pregnancy seem low. You still had another week to begin ovulation, by then the semen will be low in energy and effectiveness. I would recommend taking a pregnancy test in the next 2 weeks to be sure.
If my period was May 18 I have sex may24 then again on june 13 can I be pregnant or when can my next period be
Hi Gloria,
your next period would be expected on June 15,your most fertile days would be from may 30 to June 3 so it is possible to be pregnant if you haven’t taken a pregnancy test i suggest you do so.
Hi my last menstration was 30 may and i want to know when my ovulation will start in june
Hi. If you’re on a regular 28 day cycle then you should be ovulating from June 11th to June 15th.
I am a 23yr old female and had sex on 9th may and my last periods was on 23rd may after some milky white color discharge is coming out from my vagina…am I pregnant?
The only way to know for sure is by taking a pregnancy test. this is typically harmless if it has no strange odor or color.
My last period was May 21 don’t remember the last day but usually takes 4 days… Now this was suppose to be the 17 but i started today and its not quiet clear whether it’s a period or not but am experiencing lower abnormal pain and back pain and headache what could it be?
Hi Amanda. It sounds as though your period is just 2 days early. It doesn’t sound like something to be alarmed about. Watch to see how long your period will last. If it was only for a day, then something else might be happening but maybe your cycle is changing and it just came a bit early. Take note of it and write down the dates to keep track of your period and the days in your cycle.
The epic backache and headache could just be because your late Hun hormones are raging ( I speak from experience) however keep an eye on the flow , if it’s light and spotty or only lasts for a couple of days and hardly kicks in it may be worth taking a pregnancy test in another 4-5 days time . Equally if pain becomes unbearable the bleeding gets really really heavy with clots( sorry to be graphic) it may be worth seeing a Dr .
I came on my last period MAY 14th 2015 and it’s June 14th and still no period. can I be pregnant???
My last period started May 15th and ended May 20th. Me and my husband have had sex since than. I am supposed to start today but yet have not… however I spotted June 6, 7 and 8th than stopped just very very light spotting. I have had cramps in both my stomach and my back…i have been nauseous, and have had migraines. Could I be pregnant?
Sounds like you’re pregnant, congratulations. I’m no doctor so you might wanna get yourself a pregnancy kit. Clear blues are pretty accurate.
Yes!
Yes you could be pregnant. If you have a 28 days cycle then your period should’ve came on or around June 12th which means your period is late. Spotting is different from a full menstrual period. What you saw could’ve been implementation bleeding. Set an appointment with your doctor just to be sure of what’s happening.
Hi Mary. Plz help me. i had sex on 20th march and on the same day i took i pill. I got my period on 25 march, 19 april and 16 may. Am i pregnant.. im so worried. Thx.
Hey Sneha,
The fact that you have had your periods three months consecutively since you last had sex is a clear indication that you could in no way be pregnant. You are on the 27th day of your cycle and for the average cycle length you are in no way overdue. Wait out a few days and I’m sure you will have your periods.
23 years my period was supposed to come on 10th may and I saw small blood and had sex on that day.the next day my period didn’t come and it came on the 12th may and lasted for four days. but this month my period was to come on 7th June. but up till now it hasn’t come. have tested several pregnancy test buh they all came negative. please am I pregnant
If your cycle has changed then maybe that’s what is causing the delay. If you did get pregnant then maybe you took the test too soon. If you haven’t seen your period by now, set an appointment with your doctor and have him/her confirm what is happening.
Me and my partner are trying for a baby. I really dont know my cycle length at all. Sometimes i am on time to the date with my periods some times i can be 2 weeks late. I last came on my period 17th april 2015. And still have not come on. I have done several pregnancy tests last one about week and a half ago says negative any suggestions please x
If you don’t know the length of your cycle then how exactly do you calculate when it’s due or how late you are? It sounds as if you have irregular periods because it’s now June and no normal cycle would take this long for your next period to arrive. Home pregnancy tests are not always 100% accurate either so you may or may not be pregnant; having an irregular period makes it hard to tell. The best thing to do is to discuss it with your doctor, give him/her the dates you can remember and he’ll do some tests to figure out what’s happening and if you could be pregnant or not.
hi. i had protected sex while im menstruating on the 11 may and on 18 may i had unprotected sex so no period up to now. could i be pregnant?
I had my period in may 15 2015. But then the last one came on 8th of June and lasted for two days. I had unprotected sex in between these days.Im confused.
the first day of my last period was 22nd April, i don’t normally miss periods have been having sex since then. No period up to now, but recently took a pregnancy test which came out negative. I am feeling symptoms of pregnancy, back ache, tiredness and so forth. Could i be pregnant and how come the test was negative.
My last period was 7th May. And last April was also on the 7th.
I had sex on 27th May and 1st June.
So I was actually expecting my menses to come on 7th of june, but today is 10th june and still no period. With negative result.
Could i still be pregnant?