Don't know what to do

I don't want to come across as blunt, but it could be either of you... The only way to find out is to do a DNA test and play an open hand with your partner.

No respect for you. Sorry. That poor partner of yours

Slamming your head against a wall is what you should do. And think carefully before you spread your legs for someone else. If you don't want your boyfriend, tell him instead of jumping into bed with someone else. If your boyfriend did that, you wouldn't like it either. Well, good luck figuring out who the father is, and how you're going to tell your boyfriend that you've slept with someone else. And if you don't tell him, you're even worse.

Hi Anonymous,
What a nasty situation. It's indeed not nice to cheat, and it's definitely not handy to share a bed with both men. But you know that yourself too, otherwise you wouldn't ask the question.
From your text, I understand that you were on the pill and got pregnant because of it. So the baby could be from either of them, or from your partner or the man you had sex with. It's impossible to tell by any method, because sperm can live in the womb for a few days. In this case, only a DNA test can determine who the father of your baby is. Furthermore, it seems fair to me that you play your cards open to both partners. That way, both know where they stand. And the truth lasts longest, but in the end, the truth will come out anyway... strength...!