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
the first day of my last period was 12th of may .. my bf and i had sex on 31st of may .. will i get pregnant?
Wait it out. U R due soon. If u don’t get ur period take a test. They sell them at the dollar store. They R no different then the expensive ones. Good luck
Hello my last period was 13th of may 2015 and on the 31st of may and 1st of june and 2nd of june . I’m due on my period on the thirteen but a couples days after I had sex on 31st of may ive had back ache groin pain cramps leg ache ..could i be pregnant
hi there I had my period on the 9th of may it lasted for 3 days. then I had my other period on the 28th of the same month it lasted until 31 and on that last day of my period I had sex with my partner then the condom blasted and sperms got through. does that mean I’m pregnant?
Hey Sam,
Your cycle is quite short and thus it is quite hard to tell when you ovulate. Chances are you could be pregnant. Just take a pregnancy test to be sure.
I saw my period lately around 31 of may I had sex on 7th June can I get pregnant.
My bf and i had sex on the 31st May and I’ve been expecting my period, haven’t seen it yet. My last period came on the 7th May. Could i get pregnant, sooo sooo worried!!!
If you’re on a regular 28 day cycle, your next menstrual period was expected to start on June 04th, 2015. If a week passes by after the 4th and you still don’t see it, take a pregnancy test. You’re most fertile period for the month was more than a week prior to the date you had intercourse though so it’s not likely that you are.
Mine is exactly like yours. Have your period came? Mine still haven’t..
I had protected sex for the first time on the 5th of March. He didn’t penetrate all the way and I got my period on the 21st. It ended on the 23rd. So I took a hpt two weeks later and it came out negative. Then got my next period on 22nd April which lasted about 2 and a half days and got my last period on 13th May which ended on the 16th. My next period is in 6 days. But I feel weird. Could I be pregnant? When is the best time to take another test? I haven’t had sex ever since March 5th.
The ‘weird’ feeling just sounds like nervousness because you were new to that experience and not so sure what to expect. You got your period 3 times since your first time having intercourse and you had ‘protected’ sex at the time. Stop worrying, you’re fine. 🙂
hi, so I had sex on the 16th and 21st of May both were protected and used the “pull out method”. May 3rd – 9th I had a normal period. On the 18th through the 22nd of May I ovulated because I have irregular periods. May 30th, I took a homemade bleach pregnancy test and it came out to be positive. It scared me so I took a real test. It came back negative. My next period was supposed to come from June 1st-3rd. June 1st it did not come but I was cramping like I had to. Later that night, I masturbated and I started bleeding like a period red. I thought it was cycle so I put on a pad the next morning when I woke up it was only a drop or two on the pad of a the period look a like blood. I have been cramping since then like it’s coming but it haven’t showed up. Could I be pregnant? Is my period just late?
Your period is irregular so making an accurate calculation isn’t such an easy task but if you were expecting it on the 1st and it’s more than a week late, take another pregnancy test and see your doctor. He/She would better be able to tell you what is happening, especially with your period being irregular. Because of that, you could be thrown-off if you actually conceived. An irregular period may cause you to not know when you become pregnant if it should happen. You seeing blood for a day or few hours around the time you should be getting your period could possibly be implantation bleeding if it is you have conceived. If you haven’t had it by now, see a doctor!
My last period was April 18, 2015 and I had sex with my boyfriend on April 30th. I am 18 days late. Am I pregnant? I am never this late. I always get me period. I’m not taking any medication, NOTHING! No, stress.
Abstinence is the best thing for a young lady not married. Then you wont have to worry about it.
well that is easier said and don’t. They R on here looking for help not a preacher.
I would definitely take a pregnancy test. Thats too long to be late. But the more u worries the longer ur period takes. Good luck. I have 3 beautiful children
Hey, if my last period was the 28 of Sep, I’m not sure tho I lost track but I had sex Oct 5 with my ex and then turn around and have sex with my bf on the 12th of Oct but when I went to the doc on Nov 10th, they told me I was 6 weeks along so who is possibly the papa? Was I already pregnant in Sep?
Hi there. Based on your information that would mean you were pregnant near the end of September; around the 29th, the baby started developing. If your period was on the 28th, how long did it last? Did you notice anything different about that period, was it lighter, was there a change in color? It is very possible that you mistook implantation bleeding for a regular period. You’re not sure of the dates so it’s hard to be accurate but if you mistook that bleeding for a period and you’re last period was at the end of the previous month then you would’ve ovulated 2 weeks later around the 14th of October so it could possibly be that your boyfriend fathered the child. If the distance between intercourse with both was further apart then you could be more on point but they’re pretty close and you’re not 100% sure when you got your period so the best way to be sure is to take a DNA test when the child is born.
I would say ur ex. I’M sorry. 6 weeks brings it back to him. Good luck sweetie.
My period was on the 11th of May and I had sex on the 23rd and 27th. Please, I want to know if I can get pregnant from the days I had sex.
Hi. I am a bit worried i don’t know if I’m pregnant or not. My period started on the 20th of May and lasted for 5 days then on the 31st of May, me and my boyfriend were having fun but he didn’t penetrate so on Monday i started feeling blotted and bowel movement (loose stool) and nausea. What could be the problem?
Hi there Nam. Those symptoms could be caused by various things so it would be hard to say. You did have intercourse around the time you were ovulating but with the fact that he didn’t penetrate you, it’s unlikely to be pregnancy unless his semen got near your vaginal area. Please see your doctor for further diagnosis and look out for your period around the 17th of this month.
Hi. Me and my boyfriend had sex on April 13th, he used the withdrawal method and I’m on birth control …. But for the pass two months my period has been very light and short …. Like 1-2 days. I have taken about 4 pregnancy tests and one blood test, all came back negative but I’m still very nervous if someone could please help.
Hi Neena. If the pregnancy tests missed, the blood test isn’t likely to get it wrong. You were also on birth control so it could be that you really aren’t pregnant an it’s just your cycle that has changed but 2 days is quite short so the question is, why? It could be various things including stress, a change in your diet/hormones, etc. The best thing to do is to set an appointment to see your doctor and have he/she assess you and find out why your cycle has changed.
Thanks Mary … I also had a ultrasound to make sure that I wasn’t pregnancy …. Everything came out negative ( pregnancy test , blood work and ultrasound)
Hi. I got my period on March 30th to April 7th. Till now i am not getting my periods since two months right? I don’t know how to calculate… I did a home pregnancy test and got a negative result… Am I ovulating 40 days or not..pls help me
Seeing your period for 8 days and not having it again for over 60 days is not considered a ‘normal’ cycle so you have an irregular period, it’s NOT that you’re ovulating every 40 days. Your test came back negative and you didn’t mention if or when you had unprotected sex so the best advice is that you see your doctor. Give him the necessary dates and he/she will do an assessment, tell you if you’re pregnant or not and inform you better on your cycle and what to expect.
My period ended on a Wednesday last week. We had unprotected sex on a Thursday and on a Saturday but I cant seem to fall pregnant. When then can I get pregnant? Please help a sister.
Hi, my period started on May 8th and ended on May 9th. I started it back again today, on May 31st. Is this normal?
No. No it is not normal to say the least. A 1-day period would not be healthy or normal. It sounds like that wasn’t your actual period on the 8th and your real period actually started on the 31st instead. Your bleeding on the 8th could’ve been from something else and when that happens, it’s always best to consult a doctor to find out exactly what is happening.
My period for the first day of my last month was the 29th of April to the 4th of May. I had unprotected sex during my ovulation time. My next period exceeded the due date by two days and I saw some brownish bleeding. I want to find out if I’m still likely to get pregnant.
Please help, I had my last mentral period from the 21st to the 23rd of May and I had sex today, the 30th of May around 3a.m. I hope I cannot get pregnant because am a nursing mother and my baby is 11 months and 11days. I don’t want 2 get pregnant now. please help.
If you’re on a regular cycle (approximately 28 days), it’s not likely you would be because you wouldn’t have ovulated yet but please keep in mind, with unprotected sex, there’s always a chance for pregnancy. If you do not wish to conceive, use some form of contraceptive that works for you.