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





Hello. I just want to ask, my last period was July 14. What’s my possible fertile period? Because I’m confused about my menstrual cycle if it is 24 or 26 or 28; I don’t know, I’m confused. Thanks.
Hi. My last menstruation was June 23rd to 26th I had intercourse with my partner July 3 and 4 withdrawal method. I’m expecting my menstruation yesterday but still not coming. I hope I’m not pregnant.
Hi, my last period was June 18th and my next period was due July 13th. My average cycle is 25 days. I am now 10 days late. I took a pregnancy test this morning and it came out negative and tonight I had very light pink discharge only when I wipe and I get nauseous at night. I’m having all the symptoms of pregnancy. Should I try to test again in a couple of days??
If you are already 10 days late and the initial test is negative then you may not be pregnant. We recommend that you take the test at least one week after a missed period and you’ve already passed that. This blog has some useful information that will help you http://womanjunction.com/home-pregnancy-test/
I have somewhat irregular cycles. I’ve been trying to conceive since September. My cycles have been on
11/6
12/13
1/22
3/4
4/3
5/8
6/11
My average is 36 but they have ranged from 30 to 41 days. I should have had my period on 7/17 and am now a week late. I took a hpt this morning on 7/24 and negative. I am bloated fatigued but no other signs. I’m worried something might be wrong. Is there a Chance I could be pregnant? I did have sex several times this month.
I have my tubes tied. I have never missed a period or been late and my last period was on June 18th 2015 it is now 7/23/15. What is going on?
hi, i had sex on 17th of July unprotected sex and i was on my period lastmonth 24th-28th, if possible that I’m pregnancy or not because so confused so much….
Can a you get pregnant when you go off if it’s not completely done
I had my period on 28th of June and it stopped on the 2nd or 3rd of July. I had sex on the 4th of July. my circle is 27 days. Though we used withdrawal style but I had some sperm in me which I immediately washed off and I took Postinor 2 the next day. Yesterday I saw a little blood hoping my period is out but it stop today. Please am I pregnant?
If my period came on the 1st of July and I had unprotected sex on the 20th can I be pregnant? And what were my ovulation days?
Your ovulation says were July 13th-17th. So, the chances that you conceived are low but still possible. If you do not begin your next cycle by August 1st I would recommend you take a pregnancy test.
Hello and how are you? I saw my period on the 2nd and 3rd of June, then on the 26th of June again. I have been doing it with my husband. My period was supposed to come on the 20th of July but until now I have not seen it. Do you think I might be pregnant? But I don’t have any pain or my boobs swollen.
Once you have unprotected sex you are at risk at being pregnant. If your period did not come up to today, then now is a good time to take a pregnancy test. You had your period twice in June; this post will help to guide you http://womanjunction.com/menstrual-cycles-month/
Hi. I had my period on May 20 then missed my period in June and I thought I was pregnant but tested twice all came negative then had my period on 7 July. Now I can’t work my ovulation period because before that was on a 30 days cycle, please help. I am really trying to get pregnant. I have one kid.
Hello. I had my period on June 22-27 also I was taking clomid on the 24-28. I BD on cycle day 8 and so on. I BD this whole month well every other day and also last night July 21, 2015. I’m not sure when I’m ovulating. I haven’t take an ovulation test. I keep on forgetting. Is there a good chance I might be pregnant???
My BD days is June 29, July 1, 3,4,5,6,7,9,12,13,14,17,19 and 21. I know it’s a lot of BD. what are my chances???
I started my last period on June 18th. I have been waiting for my period and it is now July 22nd I took a test yesterday and it was negative. Any suggestions?
Give it another week and then retry the test.
Well, I am a scared 45 yr old! I always have unprotected sex because I seem to not get pregnant. When I last did I had two back to back MC. Now my cycle is a little late. Last period was June 24th. 2015. P.s I am married with one nine yr old son. I had him at 36! I know late and late. Lost my virginity late too.
Wait another week and re-take the test then.
My LMP was April 17, 2015. I’m about 14 weeks tomorrow. On April 25, 26, 27 I had sex with my boyfriend and on April 28 my ex boyfriend made me have sex with him, he pulled out wayyyy before he ejaculated. I ovulated around April 30th. I had sex with my boyfriend. He would hold it into “calm down” so he wouldn’t ejaculate. I’m stuck on whom Is the father of my baby since everything was so close.
Hi. I have a concern about me being pregnant. On July 13th my period was supposed to come but four days before that I had a change in routine on my birth control cycle so I don’t know if my menstrual period will come. I should have gotten it yesterday but I haven’t and on July 26 I need to keep up with my patch routine?
I have a 34 day cycle. I got my last period from 15th June to 19th June. I had protected intercourse on 13th July. I was expecting my period on 19th July but I still haven’t got it. What could it be?
If you had protected sex and this contraceptive method did not fail, then you should not worry about being pregnant. It could be that your period is late because of other reasons. This post will help… http://womanjunction.com/8-mess-period/
My period came on June 27 and went off on the 1st of July, which I really say 2nd because of the spotting when going off. Me and my boyfriend have had sex occasionally since then. My period is supposed to come on the 29 of July. I’ve been having abdominal pain but nothing usually with my period expecting to start in a week but what is the actual chance of me being pregnant?
Unprotected sex always increases the risk of pregnancy. Since your period is due on July 29, you can take a pregnancy test at least one week after that date if your period is late.
Well its the 29th in i woke up to no period but i do fell heavy i took a home test in it came back positive is it to soon or should i see a doctor #FirstTime
That’s good to hear! Once you’ve missed your period and tested positive, that’s a good indicator. You can consult your OBGYN. Good luck!