I could be crazy but here we go

Up until I got pregnant my fiance was always very affectionate but then it all stopped. I woke up one day and I just felt like I had been thrown away because he finally got the child he wanted. Some men are attentive during the pregnancy...not him. Even now that our son is going on 3 months absolutely nothing. We've talked with no resolve. Is it me or should I just let him take his time since fatherhood is new territory for him? Just nervous because he's cheated before and I don't know if he's up to his old ways or what.