Relashionship advice...

I really need some help… So what happened was my boyfriend and I were together for a couple months and he got drunk one night and went out and cheated on me so we ended up breaking up but three days after I left him I found out I was pregnant and obviously it was his. Well 2 to 3 weeks pass by and he begs me back and I agreed knowing nothing was going on between him and the girl before and under the terms that he quit drinking. So he agreed and stopped drinking for the most part but lately I'm scared because I asked for a girls night out last night and he was acting weird when I said I wanted to come home early and his brother never came over like he said he was going to and I came Home to a trashcan full of beers and him passed out on the floor. This morning we tried to have sex and he couldn't cum and last night his excuse was he was too drunk after he told me no all day. And he went to go to work today and was acting distant and excited to go to work which is weird for him and I tried to get a hold of him and his phone is off.... idk what to do. I dont think hes cheating but i think hes contemplating it