Blame me all you want...

I was snooping through my boyfriend's phone and came across some emails from two weeks ago that he'd sent women from craigslist. They weren't very descriptive but talked about exchanging photos and hooking up. I'm so hurt that'd he'd do this. I thought he loved me and we're having a baby.... I feel like I don't even know him now. I want to just confront him and ask why he sent those. I'm fine if he doesn't want to be with me, I have family that'll support. He never seemed like the guy that would do this. I don't know what to do.