Thanks for posting. When a couple gets back together after breaking up-- they go through a honey moon period-- this is the same period as when you first started dating...everything is perfect. Unfortunately, like we have already learned from previous experiences, the honeymoon period doesn't last.
It sounds like there are a couple of things going on here: lack of communication, you being pregnant (hormones), and the beautiful but unrealistic expectation that your boyfriend would change into the honeymoon man. Pregnancy can wreck havoc on your emotions-- things that you would maybe brush off or battles that you wouldn't fight under normal circumstances are maximized during pregnancy and it will usually end up with you crying-- all the time. It's important that you realize that some men are not attracted to pregnant women, they don't want to have sex with you when you are pregnant, and they resort to porn to fulfill that need.
Be happy-- he isn't cheating, he's by your side, you're having a baby with this man in about a month. Unborn babies feel your negative feelings and sadness- you don't want to burden your baby with this. I know it's hard because the hormones aren't really helping but you've got to try to be happy for your baby. If it means ignoring your boyfriend for the time being then so be it but you need to live a peaceful, calm, life for the next few months for you and your baby. If the problems persist months after you've had your baby (remember that those pesky hormones like to linger for about 6 months) then you can bring it up as a conversation, not a fight.
Take good care of yourself for your little ones!