The menstrual cycle
In a nutshell
The menstrual cycle is the process where the female body prepares the uterus in case it receives a fertilised egg. If an egg is not fertilised, the uterus lining will shed and cause bleeding from the vagina. The menstrual cycle lasts for approximately 28 days.
The menstrual cycle occurs in four stages. Stage one occurs on days 1−4, stage two occurs on days 4−14, stage three occurs on day 14 and stage four occurs on days 14−28.
Day | Event |
1 | Bleeding from the vagina begins as the uterus lining is shed, this is called menstruation or having a period. |
4 | The blood loss stops and the uterus lining begins to build up again. An egg starts to mature in an ovary. |
14 | A mature egg is released from the ovary, it travels through the oviduct into the uterus. This is known as ovulation. |
28 | The uterus wall is thick as it waits for a fertilised egg, if the egg is not fertilised it will be shed and the whole cycle starts again. |