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





my last period was 02 February and intercourse was on 14 February and again on 20 /21 February but I took morning after pills on 21 February …I want to know when was ovulation as on the 01 March I spotted and on the 14 March I was cramping but no periods,and on the 04 March see Dr and tested negative with sonar and urine….am I pregnant if yes when did I conceive?
I had a baby 7 months ago I just stopped breast feeding at 5 months I’m not using protection during sex just pull out method. I’ve been feeling weird not usual pregnancy symptoms just cramps in my group back ache. and nipple are really sore, lost of appetite and head aches. not sickness or anything but I did have a natural birth which put hectic on my body. so i’d like to know what this is. my husband’s worried, I already have an almost 3 year old. I’m freaked if I am but how could it be. while breast feeding my cycle hasn’t returned since birth. any chance I could be?
Hello. The risk of pregnancy is always present when you have unprotected sex. I understand that you may be nervous. You should take a pregnancy test and consult with your doctor about your symptoms.
Hi, I recently started taking birth control pills in January.I had a cycle in January on the twelfth and at the beginning of February on the fourth. The cycles were twenty-three days apart and lasted for seven days, pretty steady. I haven’t had a cycle since which concerns me. I was late a few times taking my pill and I had sex around February 19th and 20th, supposedly close to my ovulation days. Should I be concerned?
Since you did not take the pills as you should have, you might be at risk of becoming pregnant. Wait to see if your period will come. If it does not then you need to take a pregnancy test at least one week after that date.
I had my period the end of January. My tubes are tied, but I have yet to start my period. Should I think I’m pregnant?!
I had my last period on the 3rd to 6th of March and had unprotected sex from the 11th to 14th. Can I get pregnant? My cycle is 24 days.
Yes. You were ovulating at that time so the chances of getting pregnant would be high.
You are likely to be pregnant, because your most fertile period is March 11-15…please wait for another one week to test for pregnancy
My last period was 16 February 2016 when can I expect my next and when will be my fertile days.
My last period was 13th of feb normally 28 day cycle but still have no sign of March period but test says negative
Omg Toniee same here! My last period was Feb 13th as well and I’ve taken a pregnancy test yesterday which was negative! I’m always regular so this have me nervous. However, I’m spotting but still nothing. Any signs of March period for you yet?
Hi, have been so worried for a very long time, have never been pregnant all my life, and yet have never gone for any abortion. I am having issues in calculating my ovulation cycle, I seriously need your help thank you.
It is important for you to keep a record of your menstrual cycle on a calendar or on a smart phone; there are many ovulation apps available. The first day of your period should be counted as day 1.
Typically, the menstrual cycle will last for 28 days, which is calculated from day one of a menstrual period to day one of the next cycle. Ovulation typically occurs 14 days before the start of your menstrual period. If your cycle lasts for 28 days, you can ovulate on the 14th day like the average female. However, you will start ovulating around the 11th day if you have periods 25 days apart
I am 16 years old. It is March 14th and my last period was on December 22. I have had no signs of a period. No, I’m not pregnant, I have not had sex before. What could possibly be wrong?? I’m panicking!
Your period may be delayed because of hormonal or other reasons. Read our post via this link for more information http://womanjunction.com/8-mess-period/ You need to consult a doctor for an assessment to determine the actual reason why your period is late and you’re not pregnant.
At 16 my menstrual cycles skipped months and I was a virgin too…..so my mother took me to the doctor and I had cysts on my ovaries. Consult a doctor as soon as possible.
Is it possible to have sex on the fourth of September and give birth June 17th.
Yes, it is possible.
Hello, my last period was February 13-16th and it hasn’t come for March yet. Is it because February was a short month? I am still waiting. I took a pregnancy test that said I’m not prefab but I’m not sure if I did it right, (I forgot to put the cap back on after I urinated on the stick). Should I wait a few more days?
I have my menstrual 5th February. And I make love 21st February I see my menstrual on the 12th of this month and it last for one day, i don’t know what to do.
Hi am Steph,I had my period on 17 Dec till 22,always having 25days cycle but Had my Jan period on 13 lasted till 18,it returns to 25days cycle in Feb which I had 7-12 and March comes in 8-13,please what’s going on,am I having irregular periods this year I and my husband have been trying for a baby since last year.
Hi Steph, I would suggest that you calculate your ovulation day with cycle length as 22 days as your cycle is getting shorter sometimes. All the best!
I was supposed to have my period on March 7th..and now it’s March 13th and still have not had it. I’ve been having yellowish discharge and lower back pains, nose hurt, ear feels like water is in it. I took a test when I was 4 days late and it said negative…So I don’t know if I should just wait a couple of more days a take another one and see what happens?!?!
Take another test by March 18 for the most accurate results.
Hi. I had my period on the 16th of February when is my next period? December my period started on the 25th and January on the 20th.
If your cycle remains the same (26 to 27 days) then your period is due around March 12th to 13th.
Ovulation started late afternoon on the 26 of February had sex on the 28th. My period is usually lasting five days and is usually a 32 days cycle now today is day 37 no period as yet. Is it possible that I could get pregnant?
Yes, it is since ovulation typically lasts 4 days. Having sex just before and after ovulation can increase the risk of becoming pregnant.