A couple were in a bad accident.
The woman was badly injured, and the man donated some of his blood to the woman and it saved her life.
A few years later they split up and the man, in his fury, shouted at her, "And to think I gave blood so you could live."
Quick as a flash the woman ripped out her tampon and said, "Here you are you selfish bastard, I'll pay you back monthly!"
With thanks to The Cappuccino Kid for this one