For gods sake! This man is a complete sh*t! I bet he's saying now "oh honey it was a mistake it didn't mean it take me back we can have a life and a family together" yada yada yada! Have some self respect!
Was it an affair he was having or a one night stand that resulted in a pregnancy because the baby might not even be his if it's a one nighter. Sorry but either is bad! He's cheated on you. And he may not do it again, but do you want to put yourself through that agony again?
Also, did he know you were pregnant when he went out and cheated? Because that's worse and he's shown no concern about you and how this would affect your pregnancy!
Unfortunately some men (and it's quite a large amount), when confronted with the news that their spounce/girlfriend is pregnant, go out and rebel because they're just not ready to settle down and be responsible and they see it as their last chance to do it! Sounds sad, but it's true.
I'm sorry your husband is such an ***, but only you can make this decision. Don't let your fears of being alone with a baby rule the decision you make. Because babies turn into kids, and kids are smart and they know when something is wrong. And if your relationship doesn't work out then, it wont only be hard on you, but hard on the kid as well. So when thinking about how it's best for both parents to live under one roof, think how much worse for the baby it will be if you give him a second chance and it just doesn't work, either because he cheats again or you just can't get over it.
But if you choose to forgive him, forgive him. Don't keep bringing it up, shoving it in his face, because when you forgive someone, it means jut that. You forgive.