well, guys can be jerks a good number of times. LEt you in on a secret: he's scared out of his wits. I can remember myself in his situation and it's really scary. Imagine, giving up days with his buddies chugging bear while watching games or rides on the town and hooting hot chicks. All that's bye-bye for him now. It's a bit sudden but that how it is.
I'm sorry he had to see a DNA test to believe you. It's not easy for anyone to be doubted about these things.
You really did get yourself in a difficult situation but it's a good sign that he's willing to work with you. For the moment though, try not to get pregnant again. You mentioned that you'd sleep over and I guess that means sex while you're alone. Avoid that because it will mess things up a bit more.
Please be patient with him. Yes, your situation isn't the best in the world but it is what you make of it. Work together in this. Everytime you try to make him understand where you're coming from, understand also where he's coming from no matter now childish it may seem to be.
Take care of yourself and any time you need a guy's perspective, email me here.
Will be praying for you.
Erick