Why do girls have periods?
When girls are born, they have thousands of "eggs" inside their ovaries. After reaching puberty (around 11 to 15 years) roughly every month, this is what happens:
- One egg pops out of your ovary because of hormone changes in your body. You have two ovaries each side of the top of your uterus connected to your uterus by your fallopian tubes.
- It swims along to your womb (the womb is where a baby would grow if the egg had been fertilized by a man's sperm) via your fallopian tubes.
- The wall of the womb gets all thick and spongy and ready every month, just in case a fertilized egg needs to grow there.
- If the egg does not get fertilized by a man's sperm, then the egg and the cells lining the inside of your womb, come away.
- They come out through your cervix and out through the your vagina - but don't expect to see the egg because it is less than the size of a pinhead and is all mixed up with the blood and cells.