Looking,
First of all welcome here, you have found a wonderful place here, full of all kinds of help and insight. A big hug to you as you are dealing with alot right now, the good news is that it can get better. Keep in mind like you said your body is going through alot right now, and that is a beautiful thing, nothing you should be ashamed of or worry about. If your b/f is looking at other women, he is missing something very beautiful right in front of him that will one day bite him for doing. Stop worrying about who he is or isn't looking at, what he is or isn't doing and take care of you and that baby on the way. THAT is what is most important. I am a single parent to my almost 8 year old daughter, even when I was with her daddy my X, I still was a single parent, he was never in the right shape to be a proper father to her. Take care of YOU, and everything else will fall into place, one day at a time.
Many Hugs, and welcome again!