How To Calculate Your Menstrual Cycle Length

Knowing the length of your menstrual cycle is so important if you are trying to conceive.

There are only around 5-6 days a month that a woman is able to become pregnant.

If you want the highest chance of a successful conception, this further narrows to 2-3 days. 

So read on to find out how to understand your cycle 

When Does The Menstrual Cycle Begin? 

The menstrual cycle starts on the first day of your period.

If you are trying to conceive you should make a note of this each month as once pregnant the date of your Last Menstrual Period (LMP) will be used to estimate your due date. 

Knowing your LMP will also help you to calculate your ovulation, and therefore your fertile window. 

How Long Is A Menstrual Cycle?

The average cycle length is 24-38 days. Some women will have the same length cycle every time, but most vary slightly by a few days each cycle. 

Some women may have irregular periods that vary wildly in length each month.

This is not necessarily an indication of fertility issues, but it is worth discussing with your healthcare provider to see if any tests are needed before you try to conceive. 

Why Is Ovulation Date So Important?

Ovulation is critical because this is the point in your cycle where the egg is released and can be fertilised.

Once the egg has been released it is viable for around 24hrs.

After this point fertilization cannot occur, and you will need to try again next cycle. 

Sperm cells can survive in the uterine tract for around 5-6 days. 

If you are trying to conceive therefore the day of ovulation is the last opportunity in the cycle for intercourse to result in pregnancy.

Most fertility specialists recommend intercourse 1-2 days prior to ovulation to ensure the sperm cells have adequate time to reach the fallopian tubes ready to fertilize the egg. 

If you do not use birth control, avoiding sex the week before ovulation and 24hrs afterwards will be sufficient to prevent pregnancy.

You must be accurate with your dates however, so you may want to add a day or two on either end to be certain. 

When Is My Ovulation Day?

Be sure to check out this post on when to take your test