Ovulation Calculator: Understanding Your Menstrual Cycle

14/10/2014 16:20 | Updated 20 May 2015

reproductive system menstrual cycle

Our ovulation calculator can tell you when you are most likely to get pregnant, based on the information you giveabout your menstrual cycle. But do you know the average length of your cycle and understand how to calculate it?

According to NHS figures, the average woman will have 480 periods in her life, starting around age 12 and ending with the menopause at around age 52. And yet, a surprising amount of women grow up with little knowledge of the science behind how our bodies work.

Understanding how your menstrual cycle works can be crucial if you are trying to get pregnant. Our ovulation calculator relies on the information you provide, so it's vital that your answers are accurate if you want a useful response.

If this is your first time you have had to track your fertility, calculating your menstrual cycle might be a new experience. So where do you start and end your calculation?

Here's the answer: The length of a menstrual cycle is measured from the first day of your last period to the day before the next one. The average cycle is 28 days, but anything between 24 and 35 days can be normal.

So, if you're trying to conceive and you want to keep track of your ovulation cycle each month, it's important to start making notes of the date of your first period. Only by doing this can you pinpoint the correct length of your menstrual cycle.

But what if there is no average length? Most women's cycles settle into a regular pattern after puberty, but some find their period is irregular, painful, unusually light/heavy or absent.

This can be the result of a variety of environmental or medical factors, including starting, ending or changing the contraceptive pill, stress, weight changes, polycystic ovary syndrome or thyroid disorders. If you are concerned, talk to your GP.

How the Menstrual Cycle Works

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