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





Last had my periods on June 16th, had sex on July 6th & 13th, but am not seeing my period. Could I be pregnant?
Hi Edith, those dates wouldn’t have fallen in your fertile period. I would recommend a pregnancy test but if it’s negative and you still don’t see your period, give your doctor a call.
Good afternoon please I saw my period on the 26th of June so I had an unprotected sex with my finance on the 7th of July so since then i have been feeling symptoms of pregnancy like body temperature early morning, sharp pain under my abdomen, always hungry each time i wake up in the morning, always eating and eating, my eyes keep turning me…now i have been bleeding since yesterday being 18th of July so i checked my self with test strip and it showed negative… Please my question now is why was i feeling those symptoms if i wasn’t pregnant what could be the problem? Thanks
Hi Grace, there might not be a problem. It could be that you wanted to get pregnant and you are excited and your mind tricks you into thinking that you are pregnant, noticing things that you might not have noticed because you were looking for them. This is just a suggesting but that could be regular PMS symptoms.
Hello I stopped my birth control pills on June 22nd had unprotected sex until the 25th when I started bleeding until the 29th been having unprotected sex since then no cycle since the 29th been nauseated, cramping, headaches and bloated is it to early to test?
Hi Jamie, I would wake to test until you actually miss your period. You don’t want to be disappointed when in fact the test might not detect the hormones yet.
Saw my period on the first of July 2019. Made love to my bf on the 13th. Am I in the fertile window?
Hi Goli, yes you would have been right in the middle of your fertile period, which based on the calculator would have been from the 11th to the 15th. Good luck!
i had my last period on the 27 of may up till now i have not seen my cycle
Hi Mary, take a pregnancy test. If it’s negative then maybe you’ll want to call you doctor and get some tests done.
Hey I had sex June 30th & July 7 my last period was June 14th and I’m having pregnancy symptoms like tender breast and my temperature is changing like my body gets hot at night but June 11th I started bleeding .
Hi Kayla, most likely PMS symptoms. When we want to be pregnant we can pretty much feel like we are having symptoms of pregnancy even when we aren’t. That was most likely your period on the 11th, and if you want to verify that you can take a pregnancy test.
My last period was 11 June, I have 28 days cycle and I had sex with my boyfriend on 3 July. took postinor2 the next day and was to have my periods on 9 July. its 4 days now I haven’t seen my period. Am I pregnant???
Hi Claudia, a lot of time emergency contraception will affect the next cycle, having it come either sooner or later than it normally would. You are adding hormones in your body to try and prevent a pregnancy. I would recommend still taking a pregnancy test but also considering that your period might just be late because of the pill.
I saw my period on 15 of June 2019, now I saw it on July 10, 2019. Is it normal?
Hi Blessing, yes this seems normal.
I had my period on 3rd of June, I had unprotected sex with my husband on the 9th 11th 13th and 14th, had spotting on the 15th of June and also had another spotting in the 27th of June….my period was supposed to come on the 28th of June. It’s 11th July and my period is yet to start… I’ve Been having cramps and nausea for weeks now.. Could I be pregnant cause I’ve been trying to conceive since January…
Hi Linda, you could be. You had intercourse during your most fertile days. I would take a pregnancy test.
please, I usually see my period every 28 days but when i have my first sex I later see my period as 25 days. So the following month it reduced to 20 days. Now the following month I have not seen my period and. It’s almost 28 days now I haven’t seen it now.
Hi, if you haven’t seen it yet and it’s almost 28 days it could be that your period is getting back into its normal rhythm for you. I would wait until after your period would be anticipated within that 28 days and if nothing then maybe a trip to your doctor is necessary to determine if there is anything else that is going on.
I saw my period on June 5th and I haven’t seen my period yet does it mean I am pregnant?
Hi Queen, you could be if you had sex during your fertile period. Take a pregnancy test.
Hi my name is Maite. I was on my period June 14 my last day. Then we had unprotected sex June 19 2019 and again on June 27 2019 we had sex twice that day unprotected. Then I got my period on July 8 may I possibly be pregnant?
Hi Maite, if you got your period then you most likely would not be pregnant.
I saw my period may 22 to 25 and now am seeing it June 16 to 19. please with this date am I safe? Only day one has heavy flow.
Hi, you most likely are. Sometimes our periods become shorter or longer because of our lifestyles and changes and stress. Sounds normal.
My period was on June 11 then on July 4 , when is my next period ?
Hi Sophia, should have been July 9th.
I had my menstruation last May 26 until June 2. I was late last month because I had allergies and I need to drink antihistamine for it so I was late for 10 days (my period should have started last May 15). I had sex last June 13 (which is protected) and also last June 20 (unprotected but it was withdrawal). It is now July 07 and I still don’t have my period. I don’t have symptoms and I took pregnancy tests twice but both are negative. I am thinking that if I am pregnant right now it should have been a positive. Am I pregnant or I’m just stressed?
Hi Angel, it could be that your periods are late due to your bodies reaction to the antihistamines and your allergies. It’s quite normal if you are late. And yes if you are still late in a week or so take another pregnancy test. If you are pregnant the test should show it. If you have concerns or don’t get your period make an appointment with your doctor.
So me and my man hag sex all through May. Well Mary 27 I got arrested and spent almost a month in jail I got out on May 27th but while I was in jail I had a incident with a little bit of spotting and I was waiting on my period. But it never came instead I got a couple days of spotting and then it went away again and then about a week later I got a little bit more spotting. I am waiting on my period. Now which I should be getting any day but I’ve also been experiencing very sore boobs nausea the tiredness the dizziness my hormones in my feelings have been through the roof I seriously I’ve been so in my feelings and so not cool and everybody keeps saying I have a glow to me I took a dollar pregnancy test and it came back negative so I threw it away and when I went to throw the trash later on I am 50 bucket in the test fell out and now that it’s all dried up you could see what the outlining of the second positive line where it would be. When is the best time to take a pregnancy test?
Hi Tasha, the additional line one the pregnancy test after waiting and letting it dry could just be evaporation lines. However, if you haven’t gotten your actual period I would take another pregnancy test, especially if you are late with what is generally considered your period. At any point in time after implantation if you take a pregnancy test you should know if you are pregnant or not. Good luck.