Using a Menstrual Cycle Calculator

Please select the first day of your last menstrual period:

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Usual number of days in your cycle:

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 that you are at your most fertile, and thus stand a greater chance of a sperm reaching the egg and fertilizing it. One of the biggest problems people have however is knowing how to calculate their menstrual cycle. This is where technology can come in useful. You can use items such as a menstrual cycle calculator which should provide you with a rough estimate about when you are next going to ovulate. Let me tell you a little about how these 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. These types of cycle calculators often give the most accurate results, but many people find that they are ‘over kill’, and the majority of the information that they ask for is not something that people will have to hand readily, especially months of data about the subject. Therefore many women use simpler menstrual cycle calculators, which still give fairly accurate results.

The first thing that the menstrual cycle calculator will ask you is the date of your last period. Hopefully this should be information that almost any woman should be able to answer fairly easily. This will be the starting date of the last period and not the ending date.

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, and others it could be as low as 25. However, you are only after an average here. Do try to be as accurate as possible though as this will affect the results that you are given, and this of course will have a profound effect on what the calculator tells you is the ideal time to try for a child.

Finally you will be given your results. Generally you will be told the date of your next period, which should be fairly accurate. What you are going to be most concerned with however is the next ovulation period. This will be the time that you are at your most fertile and therefore stand the best chance of getting pregnant. What you do need to remember though is that the information isn’t 100% accurate as it is impossible to predict the human body, so ideally you would want to start having sex a couple of days before this, and a couple of days after.

Whilst they aren’t 100% accurate, the menstrual calculator is still a useful tool. It provides a ‘free’ way of knowing when you stand the best chance of getting pregnant, and this of course can be a god send for a couple who are struggling with this.

Learn more about Menstrual Cycle and how to to calculate it manually.

61 Responses to “”

  1. Lizzy says:

    Will like to know more

  2. please help says:

    I had my last periods on 24 june 2013 and all of a sudden on 11 july 2013 I started again but its not heavy red blood . Its startd as a pinkish brown thick liquid when I wiped myself and it kept on but the colour of my blood thinned out and it became more reder till today, what could this mean

    • Sarah says:

      Early period can be due to a number of reasons. It can be due to a hormonal change or if you are take contraceptive pills then this can also be a reason for your early period. Change in weather or body temperature can be another reason for early menstruation – which is normal. Though, if you have a pain during intercourse or discomfort in your pelvic, it is important that you get in touch with a gynecologist.

    • obazee says:

      plz i had my period jan 24th 2014 and I also saw another one on feb 1st and i want to conceive and my cycle is 24days. please what is the problem?

  3. Blessing says:

    I had my period on 5th juli and it stop on the 9th , i had sex on the 29 of the Same mouth ,and now my period has not come is it possible am pregnant .

  4. confused says:

    I am very confused. I menstruated on 3rd August & then again on 23rd August. My cycle is normally 28 days. I add severe cramps on the 8th & did a pregnancy test on the 9th and it was negative. Today is the a14th & I have still not menstruated. My partner & I are trying to conceive. Please help

  5. Curious says:

    I had unprotected S.I three days before my period was Due. My period Started this month the 5th & Ended on the 11th. I had sex once again. On the 14th and the 19th (yesterday) my menstruation cycle is 30 days. My husband ejaculated inside of me. What are the chances of me getting pregnant??

  6. SUZANNE says:


  7. mami says:

    My period always begins after 21 to 23days.it just varies is it normal?thnks mami

  8. Isabelle says:

    To am confused you and your partener must ask to God if you are trying to have à baby bcz his theone who gives children just pray and faste 2 of you and when u r on ur ovulation before u meet whith your habit pray and start thanking God for giving u à child in Jésus’s name and u will see. God bless your.

  9. Candy says:

    I was due for my Periods on 14th of Nov but worry’d ?? But shuld I ?? Or wait out over the weekend n see how how things turn out after all I am two days late ?? Plz help.. :)) Thanks !!

  10. Ob says:

    i have a hyperthyroid disease,it has become difficult to get a regular cycle for my period. It is being treated but am worried because i want to get pregnant. Please advise.

  11. Bee says:

    my period days had dropped from six days to three days 4 de past 2 months .is der anifin wrong ?

  12. Lori says:

    Well i am concern because i had my tubes cut and burnt when i had my son 9 yrs ago. My periods are always on time never missed unless i was prego. Will on 11/1/13 was my last period and we are on 12/14/13 and it still has not came. I dont feel stress at all. I would like to know if anyone has had the similar problem like me. I am 34 years old.

    • Aimi says:

      Hi Lori. I also had that kind of tubal ligation done about 2 years ago. I am 6 days late as of today and I am never late as my cycle is usually 28 days. I haven’t had any stress either. I was just wondering how it went with you. Is it possible to get pregnant even after having TL done?

  13. viola says:

    I had my last period on Nov 25 2013 and according to my app my next period is to start on DEC 12 and I have a 21 day cycle and no PERIOD please help!!!! today is DEC 19 2013

  14. Echefu oluwafunke says:

    i just started menstruating after having my daughter and my last menses was 24th dec and by d calculator i sud av started menstruating yesterday. pls help

  15. garmai says:

    My last period was December 11 with a cycle of 26 days. Is it possible that I am pregnant

  16. joan says:

    Hi, is it possible that my period last 5 days, I used to have it 7 to 8 days, is it normal, thanks.

  17. Jen says:

    Hi. I just came upon this page and I did the menstrual cycle calculator and according to this I should have gotten my period on jan22 2014. My last period was on dec 25. It’s 7 days long and 28 a days in between. Now today is jan 28 and I still haven’t gotten my period. I’m a little freak out but trying not too. When should have gotten my period? I thought I would have gotten it on jan 28 but didn’t. I’m a little confused with these dates. Need help please. Thanks

  18. Ganiyat says:

    I did the previous period on the 15/12/2014 and the last period on the 22/01/2014. When is my ovulation period

    • jasko says:

      Hi, It’s not possible to tell the exact date of ovulation by the length of your menstrual cycle. Some women ovulate around the 14th day of their cycle. However, not all women do. You can try to pinpoint your ovulation by tracking your cycles or using ovulation testing strips. You can buy those online. You can more accurately find when you are ovulating by tracking your cycles, cervical fluid consistency and base body temperature. You can find more information about this in Taking Charge of Your Fertility by Toni Weschler. You can read these posts for more info.
      One more option is to get an ovulation kit

  19. tumininu says:

    I am girl of 22,did my last period on 21/1/2014,and according to your period calculator, said I should be due for another 18/2 of this month,today is 21,and am yet to see it,Tho I had sex on 1st of this month and my boyfriend ejaculate….please is it that am pregnant??

    • jasko says:

      In this case, you would have had sex on day 11 of your cycle. It is possible that you are pregnant. However, periods are commonly late. Wait a few more days and test again. If you don’t get your period in the next 7-10 days test again. If you receive your period in the next 14 days, try consulting a doctor for a blood test.

  20. Kimmy says:

    Hi, according to your period calculator and my period tracker app I should have my period on Jan 27, 2014 and my lmp was on dec 22, 2013. Today is Feb 22 and I still haven’t got my period yet. I already tried 3 home pregnancy tests and it all came out negative. What’s happening? am I pregnant? Please help

    • jasko says:

      It is possible that you are pregnant, but we sometimes miss or skip periods because of hormone imbalances, excess stress, or many other reasons. If you don’t have your period before your next period date, it is best to consult with your gynecologist.

  21. amber says:

    I had my period the 28 th of Jan. When should I have it by?
    For my fiance and I have been trying to conceive, therefore I’ve been keeping track. I’m unsure of my exact cycle time but it is around 28.

  22. mia says:

    Hello I I stopped taking the microgyn 30pill last month had my period five days later on 30th I ovalted on the 22nd of February wen will my next period be due as worrying about becoming pregnant

  23. Renny says:

    Hi, I had my period on the 19th of Dec 2013, from there I missed my period in January, I thought I was pregnant I took a home pregnant test but was negative. on 20 of February 2014 my period stated. I have been trying to conceive since 2012 but no luck. my cycle is irregular sometime it takes up to 43, sometime more than 60. is this normal/ can somebody help me, I want a baby.

  24. favour chi says:

    today been 8 0f march 2014 is my most fertile day, when is the best time to make love and get pregnant.

  25. nouie says:

    I had my period on 21/2/2014 …and according to my P.Calculator my next period should be on 26/3/14 ….
    but Im getting these breast sores this time a li’l earlier(my signs for period)today is only 12th ….is this normal?

    • jasko says:

      Sore breasts can be due to hormonal changes, occurring any time in your cycle, whether you are pregnant or not. However, don’t rule pregnancy out until you take a test, about a week after your projected period date.

  26. melissa says:

    Hi my last menstrual cycle was on feb.18th and it lasts usually 5 days it only lasted for 4 and yesterday march 11th evening I started bleeding again what could this mean? Any suggestions? Answers?

    • jasko says:

      Melissa, I am curious about your definition of bleeding. Was it a constant flow? Was it intermittent spotting? Spotting can happen for various reasons throughout your cycle. It could also just be that you had a slightly shorter cycle this month due to changes in diet, sleep, exercise or stress.

  27. bjane87 says:

    Hey guys my last period started on the 10th of feb 2014,but there was only 28days in that month still no sign of my periods this month n its now the 14th march.we have been trying for a baby for 1 year n half n have been disappointed up to now.do u have any answers on this??

    • jasko says:

      It is possible that you are pregnant. However, it is also possible that your period is simply late. Try taking a pregnancy test. If it is negative, try taking one again. If you think you may be pregnant for some reason, and the test doesn’t show it, it is best to see your gynecologist. Just keep in mind that a missed or late period that isn’t a pregnancy, isn’t in itself a cause for alarm. Periods can be late or missed due to stress, changes in sleep or diet, or various other factors.

  28. Nwainung says:

    Pls i having hot body most especially in the midnite. Pls, some one help me.

    • jasko says:

      Hot flashes can be due to hormonal changes in your body. Hormone fluctuations occur naturally during the course of any menstrual cycle, but can also be a symptom of menopause or pre-menopause or other physical conditions. If you are very concerned about this, please check with your physician.

  29. Tunisia says:

    I saw my period last February 18th , it’s 19th today and have not come did a pregnancy test which was negative on the 17th and I have milk discharge each time I squeeze my breast….do you think am pregnant?

    • jasko says:

      While a milky discharge can be a symptom of pregnancy, it is usually not the first symptom you experience. A milky discharge resulting from squeezing the breast can have several other causes including, but not limited to: clogging of the breast ducts, inflammation, breast injury, non-cancerous brain tumors, certain medications, certain herbs, widening of the milk ducts and hypothyroidism.
      If it is a concern, it is best to address it with your doctor. Not every woman’s cycle is 28 days, and most pregnancy tests don’t work until at least four days after you expect your period. It is best to wait seven to ten days before expecting a reliable test.

  30. Yanna says:

    The first day of my last period was February 15, 2014. I had sex on the 21, which was two days before my cycle ended. I have not started yet. Could I be pregnant?

    • jasko says:

      It is unlikely that you would get pregnant that close to the end of your cycle, but not impossible. Cycles can be late or missed for several factors, some physical and some environmental. Take a pregnancy test or check with your doctor for a more concrete answer.

  31. johson esther says:

    I had a test strip 2days ago it was negative andam supose to see me period yesterday I did not see my period Å̶̷̩̥͡•̸Ϟ‎​ I pregnant

    • jasko says:

      This is a great question. Most pregnancy tests are only highly reliable four days after your missed period. Also, not every woman has a regular cycle of the same number of days each month. It is best to wait a week and test again.

  32. MARINA says:

    I have been trying to conceive for the last six years. During that time I became pregnant a couple of times, but they resulted in a miscarriage. This was three miscarriage. The doctors said that they saw an empty amniotic sac, but no baby I could not understand what was going on. Last year I had a surgery done to remove a fibroid that was growing on my left ovary, the fibroid damaged my left ovary that the doctor had to remove my left ovary leaving me with a right ovary. I am now 33 years old and I worried if I’ll ever have any children, I thought I need to hurry and try to have one fast. I went on-line in search of a product that would help me conceive fast until i met Dr. Miracle on the internet who help to cast a spell that make me conceive a baby contact him on -removed- or call him on +2347060552255

  33. Camia Granger says:

    I’ll take any opinions from any and everyone! My boyfriend nutted in me on March 27, 2014 but my period came on on March 27, 2014 . Today is April 5, 2014 . Could this period be the last period and can I still be expecting to become a happy first time mommy within 9 months?

    • jasko says:

      It is possible that you are currently pregnant, but not very likely. It would be more likely to have happened during your fertile period about five to fourteen days before your period started.

  34. prathama says:

    Hi my last period was on Feb 9 2014 at night I was back in India for month i came back here on Feb 11 2014 it’s been almost 2 months I didn’t got my periods it is possible that I could be pregnant me n my husband trying to have baby for past 6 months pls help me ??????

    • jasko says:

      It is absolutely possible that you could be pregnant. Did you take a pregnancy test? Travel and changes in diet and water, can contribute to disrupting or skipping a cycle or cycles, though. It is best to test and check with your physician.

  35. alexandra says:

    my expected most fertile period is March 25, 2014 to March 29, 2014, but if I had sex last March 14, 2014 which is the last day of my period, is it possible that I would be pregnant? I’m still expecting for my period tomorrow March 10, 2014……what should i do if it would not come tomorrow..?

    • alexandra says:

      today is march 10, 2014..my expected 1st day of period..still it hasn’t come…i’m really getting paranoid…, pls leave any reply….

  36. Ali Nasir says:

    my wife had periods on 28th march 2014 and was completed after 7 day but today she told me that she has pain and thinks that she is going to have periods again so kindly tell me is this concerned with conception pills or its natural.

  37. pooja says:

    i had my period on 13 march so i am confused whether i am pregnant or i have 2 wait for next period

  38. confused says:

    My last period was February 28th-March 2nd. Today is April 14th and I haven’t gotten my period. I took 2 at home pregnancy test both were negative. I am 31 year old latina, I’ve never been pregnant. Could I be pregnant?

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