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 , It is calculated here that my next most fertile period is January 14, 2016 to January 18, 2016. I had sex last january 21 and 22 but we used withdrawal when my partner feel that he will explode he pull out his pennis and masturbate . Is there a chance I get pregnant ? or my period will just be delayed ?
Hi. I started my period on the 3rd of Nov to the 8th of Nov. I had sex from the 9th to the 13th. From the 15th I was feeling dizzy with funny abdominal pains. Then I had sex again on the 17th but he did not come in me. When exactly did I fall pregnant?
Hi, It would be hard to give you a exact time of when you conceived but i could give you a estimated time based upon your period Possible Dates of Conception: November 13 to November 21, 2015.hope this helps.
Hi ! I recently had unprotected sex with my partner January 1, 2016 and it was one of my fertile days. I recently just had my period January 17-23, 2016 and I’ve notice some of the symptoms like acne my breast getting bigger but they aren’t tender, I have backaches headaches here and there, a little sensitivity to light, nausea and a little weight gain in my face. also my hands and feet was swollen a little yesterday do you think I could be pregnant???
Hello,Sometimes you can mistake other bleeding associated with pregnancy for a period,take a pregnancy test to find out.
I had my period on the 28th of November to December 4 and had sex with my boyfriend a few times and had sex again on the 27th of December and the next day I had my period to January 1, is it possible that I can be pregnant? The first few weeks of January I felt sick I couldn’t eat normal but now it’s January 25th, I’ve been eating a lot, I get so hungry every two hours.
Hello,If what you experienced was your period and you didn’t have sex after you saw your period you are safe,sometimes we can mistake other types of bleeding related to pregnancy in that case you would be pregnant what yo need to do is take a pregnancy test just to be sure.
still I haven’t had my period, should I wait a little longer or is it the best time to take a pregnancy test when I’m five days late? I haven’t feel anything only a little of cramps, I am 25 years old and have no kids I usually have my period every 23 days. I’m very curious about this and hoping to have a child….like I said I had my period on November 28 to December 4 and another on December 28 to January 1
ANNABEL :My period was last yr 29/12/2015, now I have not seen it. On which I had unprotected sex with my husband, I did not have any feeling of my period at all. I did urine test 4 days ago, it was positive but I’m still confused. What should I do pls?
If the pregnancy test is positive then that means you’re pregnant. Take another test to confirm if the test is really accurate. If the second test is positive then you’re pregnant. You conceived on January 12, 2016 and you should have your baby by October 4, 2016.
Had my period just this last 22nd and ended today the 24th of January. I had sex with my husband 3 days in a row until a day before my period comes. But this is the shortest period I have ever had. Yesterday was already lighter period
I had my last period last Dec.31 and end Jan 4 – cycle of 20 days I am experiencing heavy watery discharge, what does it means? When is my next period thanks and God Bless.
You must consult a medical practitioner once you have a vaginal infection. All things being well, the next period was due on January 24.
I have a cycle of 24 days only…. Is this a problem to have a cycle so short??
Hi. it’s normal to have a longer or shorter cycle than average. you can read more about this in this post: http://womanjunction.com/differences-long-short-menstrual-cycle/
I tested positive during DEC last year and later lost it due to stress and went to my doc he said no complications. 4rm DEC to Jan I had 28 days cycle and I did my period on 3rd which my ovulation period was 13th-17th I had sex with my husband during those days and now I am anxious to get pregnant. is it possible that I get pregnant? but presently I am only having diarrhea and slight cramps which come and go. can I be pregnant?
Hi,It is possible you are pregnant just wait a while and then take a pregnancy test to find out good luck 🙂
I had sex on 8th, 10th and 11th of January after my menses which started on 29th to 2nd of January. would I be pregnant now?
Hello, my first day of my last menstrual was on the 31 December 2015, I wanted to know when can I take a pregnancy test to determine if I’m pregnant or not, if possible before my due date on the 28 Jan 2016.
It’s best to wait until you miss a period before doing a pregnancy test. You can get the most accurate result if you wait at least one week after missing your period. In addition, the result might be even more accurate if the test is done first in the morning as the urine is far more concentrated at this time.
I have been having irregular periods. In November 2015, I had my period on the 14th, but had next on the 29th of December. Please I need help. Help me with the next menstrual cycle.
Irregular cycles occur for many different reasons and it can be difficult to determine when the next period is due. This article from our website will provide you with very useful information http://womanjunction.com/irregular-menstrual-cycle-occurs/
My boyfriend and I had unprotected sex on December 28, 2015. I came on my period 12-31-15 this is early and weird since I’ve had my period on 12-5-15 and wasn’t due till 1-5-16. Ever since then I’ve been dizzy and have been having cramps as if I’m on my PMS but I am not I’ve been having an increase in urination and multiple weird cravings like a tomato and I’ve also eaten oatmeal and salad. Also suffered from mild nausea but I haven’t thrown up. I’ve also been sleeping more; my boyfriend has told me I have mood swings and I’m not the same but I don’t notice that change. Could I be pregnant? What should I do?
Did you have a period at all in January? It is normal to have a period twice in a month; this depends on the number of days in the month as well as the number of days in your cycle. Having a period on December 5 and 31 indicates a 26 days cycle. If this cycle is maintained then you should have a period on or around January 25. Wait to see if you will have a period during next week.
havent started my period yet .
Hi I’m just curious if the 1st day of my last period was the 15th of last month how late am I? And can I just be late and not pregnant?
The first question is vague so a response cannot be provided. As it relates to the second question, yes your period can be late and you’re not pregnant.
I had sex with my husband on my 8th and 11th day of periods,my periods date is 28th December, but again my periods started on 22nd? Then which day is good for getting pregnant?
Hi,In order for me to calculate your ovulation date properly i would need the length of you period.
I saw my period on the 16th of January 2016 and had sex on the 22nd and 23rd, will I get pregnant? I’m on 28 days cycle.
You would be fertile from January 28, 2016 to February 01, 2016 so the chances of being pregnant would be low.