Hubby just told me he doesn't think our baby is his.

I am 13 weeks pregnant and it's been seriously rocky since 6 weeks. I found out at that time he was talking to other women and sending inappropriate pics. I have been so sick with this pregnancy and I still work 40+ hours, take care of the house and take care of our 2 other kids nonstop as he works out of state M-Th. On the weekends he literally does nothing around the house and calls me lazy because I don't have energy to do much. We planned this baby and were both so excited when we found out. Now last night I asked him why he doesn't ever want to be involved with this baby or why he never talks about it and he said it's probably not even his. WTF! I'm so hurt. I've been nothing but faithful regardless of all the times he's stepped out. I've never given him a reason to doubt the DNA of this child. How could he say something like this!