Getting pregnant (conception) happens when a man’s sperm fertilises a woman’s egg. For some women this happens quickly, but for others it can take longer.

Out of every 100 couples trying for a baby, 80 to 90 will get pregnant within 1 year. The rest will take longer, or may need help to conceive.

To understand conception and pregnancy, it helps to know about the male and female sexual organs, and to understand how a woman’s monthly menstrual cycle and periods work.

The menstrual cycle is counted from the first day of a woman’s period (day 1). Some time after her period she will ovulate, and then around 12-16 days after this she’ll have her next period. The average cycle takes 28 days, but shorter or longer cycles are normal.

The best time to get pregnant

You’re most likely to get pregnant if you have sex within a day or so of ovulation (releasing an egg from the ovary). This is usually about 14 days after the first day of your last period, if your cycle is around 28 days long.

An egg lives for about 12-24 hours after being released. For pregnancy to happen, the egg must be fertilised by a sperm within this time.

Sperm can live for up to 7 days inside a woman’s body. So if you’ve had sex in the days before ovulation, the sperm will have had time to travel up the fallopian tubes to “wait” for the egg to be released.

It’s difficult to know exactly when ovulation happens, unless you are practising natural family planning, or fertility awareness.

Have frequent sex

If you want to get pregnant, having sex every 2 to 3 days throughout the month will give you the best chance.

You don’t need to time having sex only around ovulation.