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





I had my last period on July 29. A week prior to my period I have been really nauseated, fatigue,headaches,lower back pain,I had some abnormal amounts of discharge. I got what I thought was light cramps but nothing yet. I’m 4 days late. Could it be a change in the body or should I take a test??
Hi ,
it can be both, but knowing that some women experience period even in te first trimester … test yourself. If you use a pee on a stick test use the first morning urine, it is the one with the highest concentration of HCG
Good luck
Hey my lmp was 6/30/2014 i had unprotected sex 7/14/2014 until now i still didn’t get my period its September already.i. been feeling exhausted these days,light cramps ,bloated and constipated. I took. Hpt two weeks ago it came out negative could i be pregnant??
Hi , You might be pregnant it was right into your fertile window, you can test yourself as soon you are late which 2 weeks ago was a way too early, try it again !
Good luck
I believe you are pregnant
hi please help me, my period started last Aug 22, 2014 and finished on Aug. 25, 2014, we had love making on August 26,27 and 29. it is possible that i will get pregnant. please help me, i need an advice. Thank you
Hey Zara count your first day of mens the day 10th to 17th are most fertile day if you want to get pregnant and then rest leave upon Allah try to make love immediately after your mens until day 21st.Insha’Allah.
I would like to ask my last period was July 29 until now my period doesn’t yet come.I. had sex during safe days and during fertility but we make sure we had withdraw it.and after my men’s last July 29 it stopped Aug.1.but during Aug.2-6 I had little spotting .which I don’t know why but stopped when I put some medicine. Now ,is there a possibility I’m pregnant?thanks
Hi , the withdrawal is far from being an effective method … 54 % if you really dont want to conceove you will have to discuss with your partner and your physician about the options that suit your 2 the best. As of being pregnant, it is quite possible test yourself as soon you delay for your periods, which should be by now
Good luck
Hi I had my period on the 1 of august then on the 25.of august I had sex with protection ,but there was a problem and it torn now on the 28 of it I started seeing blood like am on my period please am I pregnant or what. I am 22 yrs old.
Hi, odds that you might be pregnant are minimal, menstrual cycle is changing all along a women life and it is normal. To clear you mind out there is nothing better then to test yourself.
Have a nice day !
Hey I need help my last period was on July 30 I had unprotected sex on the August 8 , 15 I’m on a 26 day cycle and I haven’t got big p could I be pregnant
Hi , the 15 th was into your fertile window, the 8 th too early. If you delay, test yourself, with a pee on a stick test, dont forget to test yourself with the morning urine. Which will be much more concentrated in HCG hormone then any other during the day
Good luck
good morning.
my cycle is 26 days. I had my period on 7/20/14. today is 8/22/14 already and I saw nothing yet en a drop and no sign of pregnancy as well. pls what should I do?
your period can be late for several reasons. if you didn’t indulge in unprotected sex it should come soon, be patient. good luck
Help me!! So last month’s(July 2014) my period was playing games with my mind.. so my period was met to come date 16/07/14, I thought I was pregnant, I period was late for 9 days straight; then I has unprotected sex with my husband, but 10th day I started to bleed firstly it started light brown, and small amount;by the 3rd day of bleeding it got bright red color! ! And now it August period was met to come 19th-08-14
Hi , I dont know what exactlly is your question but change in cycle during a women life is completelly normal, it follow the flow … flow of hormones, stresses , routine and conception tries
Good luck
June 23-27 of 2014 period start and ended & July period was from July 19-29. when should I expect my next cycle
Hi , future will tell but you seem to have a 27-28 days cycle, if you are a regular, but you need more then 2 month to screen it right. If there is on regular patern as many women you will be an irregular, meaning that you will not be able to predict when your perios will start, you will know by your symptoms, by example for me I feel severe lower back cramp an hours before starting to bleed. With the dates you put, I dont know if there is a mistake but you had a 10 days period last month and a 2 days the previous one .. that is a big sign of irregularity…
Hi the first day of my last period was july 12 2014 and Ive had unprotected sex about 6 times since July 22 2014 but I started my period today (August 6 2014) but im usually startin about the 12-14 every month and I’m wondering since I started does that mean I’m not pregnant. I’m also having lower back cramps and have never had this before.
Hi ,
Period can lie ! If you have a doubt test yourself you will clear your mind !
Good luck conceiving !
Good day sir,thank you for this information. i have a challenge that I am passing through right now. The challenge is,have being experienced longer menstrual period since January 2014, at times is 33,32, 31, 30 and 29. pls what can i do concerning this situation. have been trying to conceive but no positive result yet.
Hi , the length of your cycle have nothing unusual nor being a reason to have difficulty to conceive. For cases like you for long cycle and irregular cycle there is a master rule to apply that can help you tracing your fertility window, that is located between day 11 and 17 of your cycle. Day 1 being the first day of your period. To be on the safe side having a longer cycle lets put your fertility window from day 11 to 21, in this window, have intimate contact with your partner no more than 1 day on 2, that way, you will have more mature spermatozoids in the womb at all time and if the egg is to be fertilised it will !
good luck.
Please reply me
I used withdrawal method and saw my menses on the said time 30th June 2014.now I am suppose to see my period 28thjuly 2014..I saw the spotting s I usually have before the steady flow but there is none coming .please what is wrong with me?
Hi , the retracting method is only 58% effective, it is most likely playing russian roulette, if you are serious about your contraception you should need a nurse of a family planning clinic for advise on what will suit you the best. Many woman will spot few days after conception when the egg attach to the womb itself, often mistaken for light period. In your case only a test will reveal what is going on. Some women will have bleeding like period for the first 3 months…
good luck
Hi
I had sex during my most fertile period,which is 18th,but my husband didn’t come inside me, will i be pregnant.
My last cycle was on June 22,2014 and they last 5 days. Normal cycle is 30 days and I should have started on July 20,2014. I have had my tubes tied in 2009 . Is there a chance I could be pregnant? How long should I wait before I see my gyno?
Hi , skipping a cycle can happen for other reason than pregnancy new gym routine, stress, exhaustion …. being tied up reduce significantly the risk that you might be pregnant depending of the technique they used. if they tied only or if they disconnected completely the tubes. more years you have your tube tied less chance you might be pregnant. If you have a doubt, at this point do a test !
good luck
Hi,
Could anxiety cause one not to get pregnant? Also is only on the second day of ovulation must one have intercourse in order to conceive? Help a worried husband.
Thanks
yes, stress can definitely impact the chances of getting pregnant. you should have intercourse few days before ovulation and during ovulation. find out more about improving the chance of getting pregnant in this article