husbands change in attitude

My husband is driving me crazy. We found out the gender and I wanted to start putting the nursery together. Granted I'm only 19 weeks and we have time. But he just isn't into it. We went to go pick out an outfit, and he was like "yeah, whatever. That's cute. Sure." 
It's starting to get under my skin. I told him that I felt the moving and stuff and he had the same reaction. Then this morning, I felt a kick. Yes, a kick. (My placenta is in my back and not in front of my stomach) You can definitely tell the difference. Anyway, he was totally not excited. I don't know what to do. Or if this behavior is normal. He seemed so excited when he found out we were expecting. I don't know what happened.