Why does this happen? Each month, blood and tissue build up in the uterus to prepare for a fertilized egg in case a woman becomes pregnant. (The uterus is the place inside a woman's body where a baby will grow.) If the egg isn't fertilized, that lining leaves the body through the vagina and the girl or woman has her period.
Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor.
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