Keeping the baby

I'm 7W4D today and this will be my second baby. My boyfriend and I have an almost 3 year old little girl together and he also has 12 year old twin girls. I told him when I found out and he told me no matter what he would be supportive. Well, I don't believe in abortion so I told him I'm keeping this baby. He ignored me for a few days and was acting so selfish. We didn't necessarily want another baby, but now that I'm carrying this child, I already love him/her so much and I can't imagine having an abortion. I feel like this should be such an exciting time, but how can I be excited when he seems miserable? He's acting like this new baby is going to ruin his life. What should I do?