Oh, I have friends like that too! Don't feel bad. I cannot say anything to them about how stupid and irresponsible they are being (notice that they are being, not that they are!) because they get upset too. I would want my friends to tell me if I was acting like an arse, but not everyone thinks the same for some reason. It is very frustrating. Especially when they do go something like a pregnancy scare and don't learn from it! Grrrrr!
Yeah, when I see things on t.V, like on er and such about women who find out they are pregnant, but are going for an abortion, so there doctor's try to talk them into birth control, and they say, "no, I will get fat..." grrrr! Whatever!
Hang in there. It is frustrating when people you are close with do stupid things like that. I know how you feel.