with my first baby my boyfriend was the same way didn't really understand why I was the only excited one about having a baby once our baby girl was here he changed and she was the most important person in his life now we are pregnant again with another little girl and he's super excited give him time maybe he will come around
He might be changing the subject cause he's in a situation where he didnt want to have the baby. You had said he wanted you to get an abortion. He may even feel guilty for telling you to do that. I would ask him but for the most part plan on being the only emotionally involved parent in your baby's life.
Oh and if he decides he doesn't want to be there for you and take care of his baby well then he doesn't deserve you or baby anyway.
No your not over reacting. Yes you should definitely continue to talk to him about it. You are Exactly right it does take time for the men to get excited and I'm sure that is the case especially since he is away and was away when you found out.. and doesn't get to see you. Send him pics of your baby bump keep him posted on all your doc apt. So he cannot distance himself from it. He's gonna be a daddy and once he sees that gorgeous baby that you were able to give him he should have a respect love and bond with you and baby that will never go away. Good luck and hang in there.
Talking with him about how you're feeling would be a good start.