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 got my period on 5/2/2015 it lasted for 10 days. I’m trying to work out when my next period is due. My normal cycle is 28 days. Will the next due date change due to a period being longer than 7 days?
Hi, the day 1 of your cycle is the day 1 of your period, if they are 3, 7 or 10 days, does not matter on the length of your cycle, nor your ovulation dates.
Good luck
My last period was this new year 2016. now it’s Feb 20 still haven’t had it. what could that mean?
Hi last month my period stayed on for 2 days with a 25 days cycle when im normally 27/28 3 – 4 days being on. My monthly changed unexpectedly and i don’t understand. I don’t know what to think at this moment because it went from 27/28 to 25 ever? I’m just trying to get a better understanding on this one.
Hello there,
My girlfriend’s cycle of 36 days has changed to 42 in the last three months. The last three dates when the period stared are: Nov 25, Jan 06, and Feb 17.
I checked the Ovulation Calculator from WebMD where I included these days, and the answer says: “The long length of your cycles may indicate that you are not ovulating.”
We are going to schedule an appointment to visit a doctor this week, but wanted your opinion as well in this matter.
Thank you in advance.
Hi , you definitely need medical assessment, long cycle does not mean that there is so ovulation, but it will be harder to track, some women with short cycle, have the time to ovulate twice in this span of time ! But be confident that if you are trying to conceive, life is always fining its way.
Good luck
Hello
I had my period on the 09 February 2015, had made love with my man on the 13-14 February then again on the 16 and 17 February 2015, he ejaculated inside me both days, when I use home test had one fainted line on Sunday 01 March, my breasts are tender and very painful and also was expecting periods on the 03 March, the GP saw bubble in my womb on the 25 February 2015. What are my chances?
Hi , a positive test will have 2 lines, fainted or dark does not matter, as soon you get the 2 lines it is confirmed, I think that you tested yourself too early, test yourself again, you will be fixed. In case of any doubt your pharmacist can help you with the interpretation of the test result.
Good luck
i had sex on February 14 and my bf came inside of me. my last period was on January 26, i take two pregnancy test and they say negative
I had my last period on January 30 and ended February 4. I had unprotected sex on my second fertile day February 28. My BF said he ejeculated in me. I’m suppose to ovulate on March the 4. I’ve been having to go to the bathroom a few times a day. My stomach feels huge like a ate a full course meal but I hardly eat anything now. Could it be possible they I have conceived or getting ready to? I am trying to get pregnant. Please help.
I was supposed to come on Feb 26, 2015 and now its March 3 and still no period me and my boyfriend had unprotected sex from the 7-13 some days he would pull on some days he won’t .. Could I be pregnant?
I used postinor2 after an unprotected sex in january and my menstural period started no th 29th of january and ended 4th of February and now feb is gone I have not seen my period. Today I took the home pregnancy test and it reads negative. Pls am I pregnant?
Hi ,
My period started on feb 1 and lasted 5 days. My husband and I had unprotected sex 12 14 15 17 and 21. could i be pregnant? My ovulation date was 19? If i’m not mistaken? I feel a bit different for the last few day. I burp a lot for almost two weeks don’t know if it could be an early sign? I’m expecting my period march 4 or 5 because my usual cycle is 32. I hope i’m pregnant.
Hi
I had an unprotected sex with my husband on the day before my ovulation period and am scared of getting pregnant please I need to know if I can get pregnant as a result of this. urgent reply needed
of course you can, test yourself. sperm can live for a couple of days…
Same situation as you , &’ my period is that same as yours . Like when it starts and ends , same 32 day cycle . Me and hubby have sex everyday and I think I got my period this morning , which I was expected to get on the 10th ..so I think my period is five days early and I too been feeling different . Could this be implantation bleeding.? ? Actively trying ! :-*
Yes, sperm can stay in you for up to 3 days.
Please help me, i saw my period on december 9th 2014 and it was 28 days cycle so i had sex on 20,21,and 25. on january 5 2015 i saw my period again and i had sex on the 13,16,19 and 22 yet I saw my period on 31 of january 2015. I had sex on 10,14,18 and on the 1st of march I saw my period again. please advice me on what to do
I used postinor2 after an unprotected sex and I had my period on 29th of January now February is gone I have not seen it. What could be the cause?
Hi, the emergency birth control pill triggers your periods. It is not uncommon that you will need an extra cycle to adjust and be back on track, Your cycle might be changed by the new one for a longer period of time as well. Nothing to worry about.
Good luck
My period came February 5,2015 and ended February 11,2015. I had sex with my boyfriend on valentines day, he ejaculated inside of me and I haven’t had sex since. I ovulated on the 17th and here it is February 27th and my nipples have been sore and extremely tender, (which isn’t even a PMS symptom of mine) this past week & a half. My period is due to come March 3rd. What are my chances of being pregnant?? (I have my fingers crossed! I’d love to welcome a little one into the world.)
Hi, life is always finding its way, but with one single intercourse, it will be winning to the lotto ! Sperm is living up to 72 hours in the womb, so it is possible.
Good luck !
Hi is it normal to have a period during pregnancy? My last period was january 29th ended february 3rd , had intercose february 17th with no protection. Now I’m confused i started my period february 23rd. By the way I have two kids boys and I never experienced this before. I’m a little bit confused about if I’m pregnant it’s been a long long wait 17years. I don’t know if my body changed. Please if someone has an answer HELP!!
Thank you.
You wont know if you’re pregnant until when you’re due. You are probably the 31st Feb. In which case wait a couple of days after and then take a pregnancy test. Then you’ll know if you’re pregnant.
hi
i m 25 years old and i have my perid on 22nd december 2014 and due to pill i have period again on 2nd january and till i have no period. and pregnancy test is also negative. this is the first time i missed my period.
Hello my first day of period was January 25 lasted for 6 days which was till the 30th. It is February 18 today and my cycle if 30 days. If I had unprotected sex on days February 2,3,4,6,8,9,10,11,12,13,14,15,16. What would be my ovulation day. This is my first month trying to get pregnant after 3 yrs of being married and finally ready!
Hi,
to conceive the ovulation window is the day 13 to 18 of your cycle, the first day of your cycle is the first day of your period. During your fertile window have intercourse only one day one 2. This will allow more mature spermatozoids to be released and increase your chances of success.
Good luck
Hi my husband and I are trying. My last period was Jan 20 lasted 7 days. We had intercourse from the time my period was over Jan 27-Feb2. It said my ovulated date was around Feb 4. We did not have intercourse day before Ovulation or the day of but we had intercourse the day after. My period is due today have not got it yet I have taken a test and it came out negative. Should I test again or am I not pregnant
Hi , to conceive it is capital that you have intercourse prior your ovulation, as the spermatozoids are living 72 hours in the womb and that the egg .. only 24h from its release to his arrival to the fallopian tube where the egg will be either fertilise or not. Eggs are very capricious so it is vital to have spermatozoids waiting its arrival and not the opposite, as the egg, does not wait. it is a matter of hours that it is degrading and not being fertilized trigger the periods. Conceiving stress can be the reason of the delay of your period test yourself again 3 days after the first test. If it is negative again, give a try on the next cycle !
Good luck
Wait a few days. The body is a weird thing. It might show up negative now because of hormones, it is best to wait a few days to one week after the period due date.