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





My period was 12/14/14 sex 1/2/15
The M.C said it should be here the 9th of this month its now the 12 should I wait or get 1 fast?
Hi my period came twice in December 2014 when will I have one for 01/2015
Hello,I had my last period 12/12/14 – 12/18 and on 12/28, 12/29 I lightly spotted once both days and nothing since. I took a test and it says negative. What should I be looking for? I just recently got off of birth control on 12/4 could that be whats affecting it? I wouldnt thinks so because the doctor said with implanon you should go back to normal pretty fast… help! Curiosity is killing me lol
Hi
tests are not lying, effectively when there is a change in the contraceptive method the body need to adjust, and most likely your doctor or pharmacist suggested you to use a mechanical methods such as condoms to make the transition smoother and safer.
Good luck
Sorry, I didnt word that very well. When I said “with implanon you should go back to normal pretty fast” I didnt mean I switched from one bc to another, I got it taken out and I am completely unprotected. Cant tell the exact dates ive had sex but a few times a week. Since I got my period once after the removal I was expecting it 28 days later but its going on 32 with nothing. I was wondering if I could be pregnant because of the 2 days I had a spot of blood. Does this explanation change anything?? TIA:)
Saw my period on d 6/12/2014, had intercourse on d 19/20.my next period was suppose to be on d 3/01/2015.but up till now I’ve not seen it.im experiencing slight headaches,back pain n’ whitish discharge.
Hi I had my period on the 10 of December. I had sex 20 through 27 of December . My period hasn’t came yet. What should I do bc I took a pregnancy test yesterday n it was negative.
Hi , test it again, possible that you test it too early or that you are late due to the rumbling of your routine, due to the holidays or the stress of conceiving. But your method is right, you have the good fertile window !
Good luck !
Hi I came on my period dec. 8 2014 and I did the estimate date when I should come on it said jan 5 2015 it is now jan 8 how soon should I take a pregnancy test
hello, you can take the test now. it’s suggested to wait from several days up to one week from when you missed the period.
Hi. I had sex on 10 th Dec. And I missed my period??? How should I know if I’m pregnant or not?
The best way to tell if you’re pregnant is by taking a pregnancy test. You can get the most accurate result if you wait at least one week after missing your period. In addition, the result might be even more accurate if the test is done first in the morning as the urine is far more concentrated at this time. The urine-based home pregnancy tests offer great accuracy.
Hi. I had my last period ended around Dec 26 and it’s Jan 13; is this the right length of time between periods?
Hi….
My last period was December 8,2014 I supposed to have my next period on January 5,2015.. But I don’t have my period yet. I use life brand home pregnancy test today and there’s two lines. One is very blue and other line is lighter blue . Is it possible im pregnant.. I don’t feel any pregnancy symptoms yet.. Thanks!
Hi , some medications can gave false positive test, if you take same medication seek your pharmacist assistance. If not congratulation my dear, it is an amazing adventure that you have ahead of you !
Good luck
I have the exact dates yu have but I do have symptoms such as fatigue sore breasts mood swings and headaches but I got a negative test so someone told me I should wait a week which Will be the 12th
Hello, my period was suppose to start January 4th but it has not. I am 3 days late. My monthly cycle is about 35 days and my period lasts about 5 days. I always get pretty bad cramps in my lower back and my boobs get really sore about 1 or 2 days before my period starts but I haven’t felt any sort of discomfort in those areas . For the past week I have been feeling very nauseous in the mornings and have had some mornings where I just sit by the toilet dry heaving. I haven’t been able to eat much this past week either . My boyfriend and I have been using the pull out method (I know it’s not a good method) for the past 2 years now and I haven’t gotten pregnant yet. We did have sex on my high peak days. Am I pregnant?
Well Bella , I strongly recommend you to take a pregnancy test if it is not done yet. Be also aware that the pull out method is not a contraceptive method, it is more playing russian roulette … as it is effective in the best cases at 75 % when the male partner have full control of himself. Please do not use this method in the future unless you want to enlarge the family …
Good luck.
My last period was December 03, 2014 and having sex on December 10th and 26th But until now January 07, 2015 i’m not having my period. It is possible that i am pregnant? My age now is 45 years old. Please reply
Hi , depending of the length of your cycle … you are at the extreme of a possible fertile window. Are you regular or irregular ? Did you just start experiencing irregularity in your cycles ? at mid life, for women as you know, menopause is not knocking to the door to present itself … it strikes when our body decide it is time !
Good luck !
I had sex on 12/31/2014 and my period comes on 1/7/15 am I pregnant?
Hello, my last period was On December 9th 2014 and i had sex on the 20th and 23, My next period is supposed to start on the 6th of January.am a little worried because am 1 day late and i have been getting this stomach cramps for the past few days am I pregnant?
Hi , well it is possible it was in your fertile window, are you trying to conceive ? If not I recommend you to seek for a family planning clinic that could help you, in case the result of the next test you will do, is not what you hope for.
Good luck
I had my last period on nov 14 2014 I had sex on 20 and 26 and now 1/7/15 I’m 7 weeks pregnant when did I conceive?
Hi to calculate your pregnancy stage they are taking the first day of your last period as day 1. You basically conceived about 15 days later if we pinpoint the middle of the fertile window you had following this last period.
Hi my last period was on December 26 2014 til the 29 not normal but been that way for some years now . what’s my ovulation date?
Hi , your fertile window starts 12 days after your periods starts and should be over about 19 days after the dau 1 of your period. To conceive, have intimate moment with your partner only one day on 2 during this window. It will allow more mature spermatozoids to be released and increase tour chance of success.
Good luck
I had a period November 26 for 4 or 5 days and then had bleeding and cramping again December 21 through the 23 and none since. Could i be pregnant?
I miscarriage a baby on nov 6th at 13 weeks and 4days my period returned normal again on December 7 to the 12 then on December 14th my husband and i tried and the 20th I am late with this period by 2 days. took a test on missed period days negative so do I wait and test again like sunday if I get no period
Hi , very sorry for your loss .. dont forget that it is recommended to wait 3 full cycles before trying to conceive again to put all the chances on your side to have an healthy and easy going pregnacy
Good luck !
Hello, I’m so confused. I had my period nov26-dec1. I’Ve been waiting for my period since December 26 and nothing so far, I took a test January 2 and it came out negative. I don’t have no symptoms. But I’m so anxious if I am. Me and my spouse had unprotected sex December 9 so that’s why I’m so anxious to know, does any body know how many days after period end do we ovulate?