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





Hi! My last period was the 29th of Aug, Sept came haven’t had a period all month. When should I get my next period? Or am I with child?
Hello. Section 2 (Delayed Period) under our FAQ link http://womanjunction.com/faq-frequently-asked-questions-menstrual-cycle-pregnancy-ovulation-abortion/ will provide you with vital information. You may also read section 6 that speaks to the best time to take a pregnancy test. You should take a test first to determine if you are pregnant.
Hi, I had my last period on September 8 to the 25th. I’m one of the irregulars and its really hard to figure out my ovulation cycle. My last period before September happened on the 1st of July and lasted til the 15th of that same month. I thought I was pregnant when my missed my period in August but I wasn’t when I found out I blessed again on the 8th of September. Im married and I’ve been trying to get pregnant for the past 3 years. Could you help me?
It is important for you to keep a record of your menstrual cycle on a calendar or on a smart phone; there are many ovulation apps available. Track your start date every month for several months – this will help you to determine your fertile days. The most fertile days in the cycle will be at least 3 days before, during and some days after ovulation. This will be the best time for you to try and conceive. Sperm will survive for 3 to 5 days while the egg will last for 12 to 24 hours. You are fertile for about 5 to 7 days.
Can someone please help ….. my menstrual cycle came on 9/11/15 however i came across some bright pink blood on 9/30/2015 which is gone on 10/1/2015 is it possible that im pregnant ?
Hi Shanna, If you had unprotected sex yes it is possible.
Hi my last period was 12 march and had sex with my bf on 29 march. could I be pregnant during those days.
I finish my period on the 26th of September and I have sex on the 1st of October and he poured on me can i get pregnant
I had my period September 1st. It usually lasts 5 days. I have my cycle every 28 days. I should have started my period September 29th. Could l just be late or pregnant??
Hello. The best way to determine this is to take a pregnancy test 1 week after you’ve missed a period.
Last month periods were late by 15 days.. So upcoming periods can be delayed by how many days??
Hello. There is no set amount of days that a period will be delayed for. It all depends on your body and the emotional and physical changes that you are experiencing.
My last period was on the 1st September, I had unprotected sex in the 17th September did not take the morning after pill. I usually bleed for 6 days, I took a pregnancy test over the weekend and it was negative. I’ve been getting pains in my lower back, feeling tired my cravings have been odd I get this weird taste.
My period was from Sep.2- Sep.7
We are trying to conceive. For the last week my breast have been really sore and heavy. I’m bloated, nauseous, tired and can smell everything. I’ve been having cramping and increased discharge. I took a pregnancy test on the 25th and 27th, they both were negative. I haven’t started my period yet. Could I be pregnant?
Hello. The biggest sign of pregnancy after unprotected sex is a missed period. However, this missed or late period is not a sure sign as there are many other things like stress, sickness and fatigue that can delay a period besides pregnancy. The best way for you to know if you are pregnant is to do a pregnancy test. These are easy to get nowadays because they are available at drugstores or health centers. It is important to note that the home pregnancy tests are ninety-nine percent accurate if taken after you miss a period.
I had my period on 4 of Sep and now I’m seeing it today. How can I know my next period and is it normal?
It seems you have a 26 days cycle at this time. Bear in mind that cycles can change at any time. If your cycle remains unchanged then your next menstrual period is expected to start on October 26, 2015.
Hi may God continue to increase you. my period would be in 6 days. I am anxious and want to go for a blood test. would pregnancy be detected if I do a blood test today? help pls.my cycle is 32 to 33 I saw my last period on the second of september I had sex with my hubby on the 18th and 20th of september. what are my chances of getting pregnant
Hi Mimi,yes it is possible to become pregnant if you had unprotected sex. you should wait until you miss your period then take a test if its negative then you go in for a blood test.
Hi , my period came on on August 31 and ended September 5. But the calculator saids my period comes on September 28 & my period is 2 days late. Am I pregnant? My period always comes on around the 6 or 7 of every month
You can wait a few more days to see if your period will come by October 7.
Hi. I had my last period from 2nd-6th September then I had unsafe sex with my boyfriend on 8th September my cycle is 26 days I haven’t seen my period as of today am I pregnant?
Hi. Please wait a few days to see if your period will come. The best way to determine if you’re pregnant is to take a pregnancy test 1 week after you’ve missed a period.
Hi. You were most fertile period on September 12 to 16, 2015. It is possible that you’re not pregnant. Wait until a week has passed and take a pregnancy test then.
Had my period August 26-30 I haven’t seen my period since its now September 30th. Could I be pregnant? I tested 25th – it was negative. Do I need to test again and if so when is a good time?
It is possible that you may not be pregnant since you’ve tested negative a month after your period was due. If you missed a period and you are not pregnant, you might want to know why this happened. Some of the causes of a missed menstrual cycle include: stress, change in regular schedule, travel, illness and use of certain medications. It would be best to consult your doctor for help in identifying which factor is causing the delay.
My last period was 8/25/15.. My cycle is 35 days according to my calendar.. I didn’t have my period on 9/28/15; I’m a day late. I’ve had unprotected sex without him ejaculating in me. Should I take a pregnancy test or wait a few more days for my period?
Wait a few more days. The best time to take the test is one week after you’ve missed a period.
Hello. Assuming I saw my period on the 9th September. The next time I will see my period will be 3rd or 4th of October and ends on 7th or 8th October. Pls is it right to be seeing my period that way?
Yes, it is okay. Based on the dates provided you have a 25 days menstrual cycle.