baby daddy drama pt2

I need advice so I posted the other week how I found out that my baby daddy who I've been with was cheating on me well we decided to try and work it out start over and get through it well now all that has changed because one of the girls he was having sex with just sent him a positive pregnancy test and says it's his we just started over and I moved in idk what to do now I'm 13 weeks pregnant with our little girl and we've been out shopping and our families are so excited he told me yesterday and I literally couldn't stop crying the whole night I made myself sick from how upset I got about the whole thing. Someone give me advice on what they would do if they were in the same boat as me