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, i got the merina coil out on the start a january i had a normal period on the 31st lasted the normal 5days.. then nothing until the 1st march which was like brown discharge only enough for a panty liner lasted 4 days and when i peed and wiped it was a light pink colour.. made an app with the doctor the following week and negative test it is now the 20th march.. is this normal as i am tryin to conceive
Hi there Stephanie, if you period does not return as normal within the next 5 days then do not hesitate to repeat a pregnancy test.
I’m late in my period for three days I have tested and it’s say negative .would I been still pregnant.
Hi Mary, missing your period 3 days does not only mean you are pregnant. Could mean quite a number of things. If you do not have a period within 7 days then take another pregnancy test.
Hello I’ve got my last month men’s on the 14th of Feb but till now my menstruation still not arrive do you think I’m pregnant?
Hello there Criz, if your period does not return within a week then take a pregnancy test.
My period start 17th and ended 19th why is strange to me it has never happen before
Hello Mercy, is there anything new that happened prior to the starting of this period? Has this ever happened before?
Hi, am 26 yrs old, my period is a 28 day cycle and I bleed for 3 days. Before it wasn’t regular but became regular for like 6 months now. Now my problem is the flow….it’s usually little or scanty flow. But I have menstrual cramps, purging, waist pain when menstruating and when I ovulate….I hve waist pain and cramps as well. What should I do? Should I be worried about my flow not being much.
Hi there Cheesy, an extra light could be as a result of various things: being underweight, maintaining a bad diet, stress, etc. See your doctor if you ae very worried about this new occurrence. All the best.
I had sex on july 10 2016 and July 12 2016 my due date is April 15 2017. which date from my sexual intercourse cause pregnancy? thank you
Hello Shie, to find out the day you conceived use the following link: http://womanjunction.com/conception-calculator-find-your-conception-date/
Hy Steffy,
I’m Esther , I had unprotected sex with my bf on 2nd of January this year and I took postinor-2 and my period came well in January and February. I had sex with him again on 13th which was a day before my period and I took postinor-2 the next day which was supposed to be my menstruation day but I’m 5 days late could I possibly be pregnant? Took a pregnancy test yesterday which was negative
Hello Esther, Plan B can modify the usual start date of a period. However if your period doesn’t return, retest in 7 days.
Good day I had my period on the 28th jan n then again the 11 of feb I’m off the three month injection for six months m I took birth control twice in March it’s the 19th of March should I be worried
Hi there Melissa, if birth control is not taken properly or consistently then pregnancy can occur. Take a pregnancy test to confirm.
I had sex from 2/10/17-2/14/2017 got my period 2/18/2017 should I be concerned as I have not gotten my period this month?
Hi there Olga, if you do not have a period in 5 days then take a pregnancy test. All the best.
Hi there. I am now 37 weeks pregnant and my last period started on the 1st of July 2016. However I had sex with my bf everyday between the 8th to the 11th of July 2016 and then I had sex again with someone else around the 21st of July and according to the app my most fertile days are from the 11th till the 15 of July 2016. I am abit worried as to who the dad is. Please help
Hi there Sam, to find out your date of conception use the following link. All the best. http://womanjunction.com/conception-calculator-find-your-conception-date/
Hi good day…
My period came Feb 13-18 2017 ,my fiance and I had sex a few times between Feb 25 and March 5…..
I normally have my usual breast tenderness and a little bloating before my period starts .. but there was only bloated feeling for a few days….
Woke up this morning march 16 to what seems like my period….
Am I in the clear now that I see this?
Or there’s still a chance I might be pregnant?
Hello MpK, if it seems like your period and you did not have a pregnancy result that marked you as being pregnant then yes you are in the clear.
Comment Text*my period is 2 days late can i be pregnant
Hello Ramat, if your period does not come within 5 days then take a pregnancy test.
My last period was 13th Feb I’m on a regular 21 day cycle/on time (except last month) for some reason I was late on a 28 day cycle?!? my period was meant to be due 6th March (21 day) – still waiting…So now the 13th has passed (28 day) and still nothing! Don’t want to get too excited as I did last month…I’ll grab a test in the weekend.
Hi there Sunshine, I hope you are pregnant, however to confirm kindly do a pregnancy test.
I have a 30 days cycle ..Jan 17th was last month period date , Me n hubby had safe intercourse(condoms) on Jan 30th,Feb 6th, 11th & 15th 2017 and got my period on Feb 23rd which was a week late and drove me crazy with severe pregnancy symptoms until it came up. Still have symptoms like cramps ,back ache fatigue and metallic taste .. could I be pregnant even after getting my cycle?
Hello Shailee, yes many women bleed even while being pregnant but this is not considered a period. Take a pregnancy test to see if you might be pregnant.
I seen my period last February 14th to the 19th here it’s march 20th and it haven’t came on yet why is that??
Hello Kimyatta, many things might delay a period including stress, change in hormones, pregnancy. If it does not return within 5 days then take a pregnancy test.
I saw my last period on 30th of October and it ended on 4th of November and I had sex with my ex on 9th of November and had sex with my bf on 11 of November to 22nd of November, who is the father of my child
Hi there Ufondu, please use the following link to determine who might be the father for your child based on the conception date you mentioned: http://womanjunction.com/conception-calculator-find-your-conception-date/
I am late in my period for two day. my heart is beating fast. I dont like the taste of food and water. My stomach is hot I feel tired and sleepy. Am i pregnant?
Hello Mabel, you just might be pregnant with all those symptoms you just listed. To confirm this take a pregnancy test. All the best.