How your menstrual cycle works

How your menstrual cycle works

A normal menstrual cycle can last from 21 to 35 days and may vary from month to month. Day one of your cycle is considered the day that your bleeding starts and it’s common for this to last up to seven days. In women who have recently started their periods, cycles can be longer and tend to get shorter with age.

Last reviewed: 19/12/2019 by Dr Simran Deo