I need someone to speak to..

So while me and my boyfriend are having a baby, he's living in my mothers house until May we already put money for a spot so I think that being pregnant is a lot of mood swings.. So tonight I've found out that he's talking to a girl and told her when can they meet up ? 
I don't know how am I supposed to feel, I keep crying to think about what can I do ? Should I keep my baby ? Or should I get an abortion ? We've been together for 4 years. I'm so lost right know someone please help me..