Mensturation
Sometime during puberty, girls start their mensturation.
After the first menstruation, a girl can get pregnant.
The menstruation approximatly happens every four (4) weeks.
Words with same meanings
period
menstrual cycle
time of the month
menses
Detailed explanation
When a girl becomes older, an egg develops every month in her ovaries.
If that egg is fertilized by sperm, a baby is created.
A thick mucous is formed as a precaution for the egg.
The egg nests in this mucous.
If the egg is not fertilized, this mucous is not needed.
Then it dissolves.
This makes the uterus sore and bleed.
The body uses the blood to flood the mucous pieces out of the body.
The vagina is used as an exit.
That is the reason woman normally bleed once a month.
The body gets rid of precautions that are not needed in that month.
When woman get older (around 50 years old), the bleeding stops.
This means they cannot have children anymore.
This process is called the menopause.