During puberty, the female reproductive system begins a process called the menstrual cycle. Girls start to release eggs from their ovaries and begin menstruating, a process also known as having a period.
The menstrual cycle begins with the growth and thickening of the uterine lining, which creates a suitable environment for a fertilised egg to implant and grow. The cycle typically lasts 28 days, but it can vary in length from month to month and between individuals.
There are four main stages of the menstrual cycle:
Fertilisation is the process of combining the male gamete (sperm) with the female gamete (egg). If fertilisation occurs, the fertilised egg implants in the uterine lining and pregnancy begins.
Tracking the menstrual cycle can be helpful for women who are trying to get pregnant through sexual intercourse. Ovulation typically occurs around Day 14 of the menstrual cycle. This is when the egg is most likely to be fertilised by a sperm cell.
If fertilisation occurs, the woman will become pregnant and her menstrual cycle will stop. The uterine lining will remain thick and she will not have a period while she is pregnant.
Monitoring the menstrual cycle can also be useful for women who are trying to avoid pregnancy. This can help them identify their most fertile days and use protection or avoid sexual intercourse during this time.