If you have reason to believe that your H is not sleeping at home and an EA/PA is a deal breaker for you, why haven't you done anything about finding out one way or the other? Ignoring something doesn't make it go away.
I understand that you have a lot going on right now with the pregnancy, but I think you do need to ask yourself what your deal breakers are. Because things are only going to get crazier after the baby is born and you will be highly emotional and sleep deprived--not exactly the best recipe for acting rationally. Better to make a plan now so you have something to follow.
Personally I think the red flags for OW are there. I also think you must protect yourself and your child legally and financially. Get that child support agreement in writing ASAP. If necessary, file for D. Just do NOT trust your H to do the right thing no matter what he says. Better safe than sorry. And D is not an insurmountable obstacle to you reconciling.
If you love somebody, set them free. http://tinyurl.com/2empx2g
