Right time for sex

A few days before ovulation, you may notice your vaginal mucus becomes clear, slick and slippery, and feels a bit like egg white.

This is a sign that ovulation is about to happen. It’s the best time to have sex, as sperm travel more easily in this kind of mucus.

You can use a predictor kit from a supermarket or pharmacy, to test your urine for signs of ovulation. If you start testing your urine a few days before the day you next expect to ovulate, a positive result means you are going to ovulate within the next 24 to 36 hours (one to two days).

Some people think the ‘menstrual cycle’ and a ‘period’ are the same thing.

A period is when you bleed (or menstruate).

A menstrual cycle starts on the day when a period starts (day 1) and ends the day before the next period. A cycle’s length is considered normal if it’s between 21 and 35 days. They can vary between women and from one cycle to the next.

If your menstrual cycles are different lengths (most women’s cycles are) you can work out your average cycle length.

The number of days in a woman’s menstrual cycle can vary month to month. Periods are not always regular. It can be useful to work out an ‘average’ cycle length, based on the length of three menstrual cycles, to estimate when you’re most likely to be ovulating.

If you add the number of days in three cycles and divide the total number by three, it gives you your average cycle length.

Example

Sarah tracked her last three menstrual cycles by counting the time from the first day of one period, to the day before the next period. 

Cycle 1 was 28 days; Cycle 2 was 32 days; Cycle 3 was 27 days

28 + 32 + 27 = 87

87 divided by 3 = 29

So the average length of Sarah’s menstrual cycles is 29 days.

When you know your average menstrual cycle length, you can work out when you ovulate.

Ovulation happens about 14 days before your period starts. 

• If your average menstrual cycle is 28 days, you ovulate around day 14, and your most fertile days are days 12, 13 and 14.
• If your average menstrual cycle is 35 days ovulation happens around day 21 and your most fertile days are days 19,20 and 21.
• If you have shorter cycles, say 21 days, ovulation happens around day 7 and your most fertile days are days 5, 6 and 7.

Your most fertile days are the three days leading up to and including the day of ovulation.

Some women have very irregular cycles or find it difficult to work out an average cycle length. This can make it hard to work out when ovulation happens. If it’s all too hard, having sex every 2-3 days covers all bases and improves your chance of getting pregnant.

• American Society for Reproductive Medicine, Optimizing natural fertility, https://www.reproductivefacts.org/news-and-publications/patient-fact-sheets-and-booklets/documents/fact-sheets-and-info-booklets/optimizing-natural-fertility/
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