On a relationship break..?

My boyfriend and I have been dating for just over 2 years and have been living together pretty much the whole time. we are both 23 I am currently 5 months pregnant with his baby. I know we have been agruing alot, and I have been emotion and telling him i need him there for me. It seems every weekend he hangs out with hs friends and does not come home until the next afternoon or evening. Even though I am pregnant and ask him to please come home after, he has never come home after in the last year that we have lived here. He says were not married and he doesnt understand why I care. But Anyway when he doesnt come home I get worried and sometimes acuse him of cheating. So the last time he went out i accused him again over the phone and he said its over. the next day he came home and grabbed some things and told me its a break, he wants to be single and free and not have me tell him what to do. and he loves me and only wants some space. It hurt me so much as I was so shocked and its been so hard on me, he ended up coming back and taking everything. he has moved in with the girl i thought he was cheating on me with and that hurt soo bad. this all happened within the last week. He insists he is not seeing her or fooling around with her or anyone, he says he doesnt want us to see other people, and he loves me more than anything. he just needs space , and is unsure if he will come back or not, but says we will be together agian. I feel so worried and I want him back more than anything, I am wondering if he is just saying its a break and he love me and says he isnt seeing her or anyone just to be nice, but if it was over wouldnt he just tell me hes seeing someone?. I do believe what he is saying that they are only friends and roomates, but its so hard to accept. Is there a chance he really does want to get back together? I am soo confused please help. How can I get him to want me back, I am such a great girlfriend i do anything for him, and only ask him to come home when the partys over instead of sleeping there.and accuse him of cheating which i know he hates. I want him to miss me and want me back and not make me feel worried.