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 there,
Am 34 years old and am looking to conceive again but I have tried so many time but without success. When I was 25 I had a surgical abortion since then am not about to conceive again I need advice please. I am worried and I need a baby
Thank you
hi, please check this post for some tips
I had my last period from the 15 of Jan through to the 19 I’ve been having on and off protected sex with my husband it’s now the 18th of Feb and my period have not started yet should I be worried??
Hello Kay, According to the information you provided you were most fertile between the 25th and 29th of January. Pregnancy is always a possibility when having unprotected sex. Good Luck!
My last period was jan 23rd and my husband and I started trying for our 3rd baby we had sex the 3, 5, 7, 9! My period should be on the 20th of February but we are praying we are pregnant. do you believe we timed it well and conceived?
Hello Jenn, Your timing was pretty good. According to the information you provided, you were most fertile on the 5th of Feb. Good Luck to you!
My last period was on the 24th January 2016,and had unprotected sex on the 31,1,3,5,6,8,11 is there any chance of me being pregnant. I really want to be sure of myself.
If you have unprotected sex, you can get pregnant.
not if your pullout game is strong
Hi I was supposed to have my period on 16 Feb but I have still not had it I feel am having the symptoms of getting my period I had a urine test but was negative. Please can u still ve a negative results and still be pregnant
Probably not, check our FAQ page for some reasons on why your period might be delayed or skipped.
I had my last period on the 18th Jan 2016,had sex on the 29,30 and 31st Jan 2016…I haven’t seen my period this month could I be pregnant?
depending on your sex life, you could be. I would recommend tracking your period, and taking a test if it never shows up.
Last January, I was 7 days delayed and had my period on Jan. 12. Usually, my cycle is 30 days. This month, I’m 8 days delayed. I’m not having any symptoms of pregnancy. My boyfriend and I are sexually active. We had protected (condoms) and unprotected sex but when we enganged in unprotected sex, he always withdraw. Could I be pregnant? Or could my cycle change? I was sick from Jan. 30 – Feb. 1, could this effect the change in my menstrual cycle?
Honestly, it is probably a change of cycles. Keep an eye open, and track your cycle. I’m sure everything will be okay 🙂
Pls I want to know when is the right time for one to have sex without getting pregnant? I had my last menstrual period on the 26th of January and it finish on the 29 of January.
Thank u
Have protected sex. Unprotected sex at any time can lead to pregnancy.
Hi I noticed blood on October 6 2014 and its 2016 and my period has never come back since October 6 2015 is it normal?? im 12 and im scared please reply..
Please go to the doctor.
Hi my last period started on 24/02/20216 and I have this mood swings and certain food aversion and I can’t go without eating hot wings each day,chocolate and cake and am not a sweet tooth person but this days.could I be pregnant
If you had your period, and haven’t had unprotected sex, then no you are not pregnant.
I did have unprotected sex two days before my ovulation. I slept with him on the 2/02/2015 and my ovulation was from 5/02/2016 till 9/02/2016.still haven’t had my periods
I would wait a week after your expected period, and if no sign then I would recommend taking a pregnancy test.
My last period was on 13th jan 16 to 17th jan 16 and I had a unprotected sex with my boyfriend on 21st jan and after 1 hour of my unprotected sex I took 1 ipill. This month my period date was already over but not yet start.so is there any problem ? And is their any chance to pregnant???
You took the pill so no you shouldn’t be pregnant.
We have been trying to get pregnant for almost a year now. We had a mc in July last year. My last first day of my period was Jan 23 and we had sex through the whole month. I’m due to have my next period on Monday. We had sex on Feb 4, 8, 11, 12, and the 13. Is there a chance we hit my ovulation day? I hate to be worrying about this but we’ve been trying for quite awhile now. I’m getting a little discouraged that I haven’t yet gotten pregnant. How early can you tell if you are?
Yes there is definately a chance (YAY!!). Do not be discouraged, as I know it can be frustrating to concieve. You can tell one week after your missed period.
Thank you….hopefully I know soon!
Hi I had my period on Jan 19 I had unprotected sex Jan,28,29,30 31 feb,1 3 ,4 I usually get heaviness in my breast before my period comes today but I don’t feel a heaviness in my breast I rather feel sharp pain in my left lower abdomen pls what does this mean
You might be pregnant Lisa. I would track your cycle, and take a test 7 days after missing your period.
My partner started her last period on the 9th if Jan. We’ve been having sex. She hasnt seen her period yet. And she complained of severe stomach pains this night. Similar to mentrals cramps..but this is severe according to her. Could she be pregnant?
Since you had unprotected sex, yes, she could in fact be pregnant. I would recommend taking a pregnancy test as soon as possible, and going from there. Good Luck!
I has sex with my boyfriend in July 27 2014 and fell pregnant! I gave birth to a healthy baby boy on 16 June 2015. Ever since there had been problems in our relationship as I am thought to have cheated on him but I didn’t! How long is gestation period other than 40-43 weeks? We also went for paternity test with the results of 98.99%! My boyfriend does not want a second opinion as to the probability should be from 99.99% – 100%! Help me!
The baby is his, end of story. The paternity test wouldn’t have been so high if it wasn’t his. Talk to him, and if he still accuses you of cheating you need to make some tough decisions. Good luck dear, I wish you the best.
I saw my period on 28th January and ve sex on 9th February could I be pregnant. Cause I feel something heavy in my chest, weak
Hello Vivian, if you have unprotected sex, you could become pregnant. Track your cycle, and watch for changes.