What is the worst misconception about the female body a man (or woman!) has told you?

Dina

My ex boyfriend told me that i couldn't get pregnant standing up because gravity...BUT if I laid down within 2 hours after, i would get pregnant that way. He said if I got pregnant accidentally, that he would just have sex with me again because sex during pregnancy kills babies.

He got a long lecture after that.

Lol who comes up with this and decides its fact!

What's yours?