Starting your periods is a major milestone of puberty and means that you can now become pregnant. You can expect to have a period every month until well into your middle-age.

Scared? Squeamish? It helps to know the science behind your cycle.

As a woman releases an egg each month, the lining of her womb becomes thicker to prepare itself for pregnancy. If the egg is fertilised, this lining will then gently cushion the egg as it develops into a baby. If the egg is not fertilised, both the egg and lining leave the woman’s body through the vagina - and this is what causes the bleeding you experience during your period.

Click here for a closer look at your menstrual cycle.

Being clued-up on your cycle means you’ll be better prepared to deal with your period. You’ll know when to carry tampons or pads and how to recognise and relieve period pain.