Opinions needed?

Courtney
I have a friend who has been very promiscuous , and she now claims she is pregnant. She told one of the guys there is only two possibilities and the other that he is for sure the dad. I told her i didn't want to be her friend anymore because I think it is so disgusting she would lie. Am I in the wrong ? Should I stay out of her business and stay her friend or do I have a right to think that's inappropriate ? It doesn't only effect her, but the child she may be carrying too :(