L.C.
Just a couple things:
1. Lots of times when men are getting ready to have babies the just freak all out. There life is about to change and they know it. They are desperately grabbing for all of the things they think they will lose when the baby gets here. This can happen even when the baby is planned.
2. Mommy gets thoroughly p.o.'d because everything in their life has changed. They don't look the same or feel the same and this baby is already a reality for them. Then here is this guy and NOTHING has changed for him. He doesn't look different or feel different he can go out and do what he wants when he wants. It is frustrating and scary, because what if the baby gets here and he STILL feels this way.
You need to find time to sit down with him and talk about this when you guys aren't mad. Address his fears first. I wouldn't call them fears or he might get defensive. Call them "concerns." Let him know that you can work things out where you give him time to be a guy doing guy things and he can give you time being a girl doing girl things. Tell him you can work it out so that he gets a certain ammount of time a week and you get the same. Then explain to him the things that WILL change that you can't do anything about. No leaving at the spur of the moment. No sex at the spur of the moment. Things will have to be more structured so that everyone is happy. But it is doable. Tell him you need his support right now, because you are feeling concerns about the changes too and you need him around to make you feel safe about the fact that you two are able and willing to handle those changes. This can be fixed if you communicate and he is really committed.
If he isn't committed, you are better off changing the living situation now rather than later.