It may seem unfair that girls get periods and boys don’t, but it’s because their bodies are different. Girls have reproductive organs which include a uterus, ovaries, fallopian tubes, cervix, and vagina. Boy’s have a penis, scrotum (sack), and testicles.
For girls – every month, the lining of the uterus thickens and prepares for a fertilized egg. If the egg doesn’t become fertilized, the lining sheds and blood is released from the uterus. This is called a period.
So, having a period means that you’ll likely be able to get pregnant. Guys have different reproductive organs, so they don’t have a period and therefore can’t get pregnant. Some guys may actually feel that this is unfair.