How many women have been cheated on while pregnant? And how many stayed? How do they handle it?

I had 3 expectations when I got pregnant. 1 to be in my late 20's 2 Have a caring partner to be there for me (cravings foot rubs etc.) 3 To be married. I got one of those I am 28. My boyfriend decided on our 4 year anniversary to get me pregnant. From then it has been one thing after another. His mother called me an alcoholic and said I couldn't be trusted to have his baby. She kept comparing me to her when she was pregnant and continued to drink. Yes I drank maybe 4 nights a week before I found out I was pregnant but then I quit and I quit smoking. She even went as far as recommending me to a free clinic that specializes in abortion even tho she knew I had health insurance. She could have recommended an OBGYN. After that drama we decided that we needed a bigger place because we have a baby coming. My boyfriend works 2 jobs so he can pay child support for his son that he had before we met, as well as pay our bills. So being 4 months pregnant and packing an entire house by myself on top of working 50 hrs a week was stressful. He got 2 friends to help move our big stuff but they only moved a portion of it due to one of his friends being sick. So I paid some friends of mine to move the rest so I didn't have to chance leaving anything behind. I then had to clean the new house before moving in and clean the old house after moving out in a matter of 2 days. I really needed support from him. Well at 5 months pregnant on Thanksgiving I had to go into work that night because I worked in the mall and day after thanksgiving was our busiest day. I go to take a shower to get ready. When I come out I stand next to the couch as my boyfriend is playing a video game I glance down to see a text in his phone from a girl named Ashley. So I pick it up and read it. I'm the message he asked her if he had a chance with her... I said WTF is this? Who is this? Why are you asking her if you have a chance with her? Why did you get me pregnant? All questions have no valid answer. He said he was done talking to her he was playing with her, it won't happen again. OK. I gave him the benefit of the doubt and let it go we are going to have a baby together I gave him an out but he stayed. Well come December his birthday is 3 days after Christmas and he is getting ready to go out with friends. I again happen to be by his phone when a text message comes in. It is a picture of a blonde girl in a red dress the text says Happy Birthday! I ask him again who is this? I don't know who that is. How does she know it's your Birthday and have your phone number then? I don't know was his answer. So I sit home alone that night stressing over it. I then get a message from a girl on Facebook telling me that he doesn't want to be with me and starting all kinds of drama while I am at work 6 months pregnant. He doesn't know who it is because it is a fake profile. I find 4 other profiles with her picture so I stopped talking her to thinking it was just his baby's mom being immature. I then am in his phone constantly my trust has already started depleting. By February he has a phone number in there that he claims he doesn't know but keeps calling him while we are spending our little amount of time together. So I get curious and I enter the number into Facebook to find a pregnant girl's profile...Hanna she is due 4 days before me. I ask him who she is. He gets defensive and denies it as I scour her page I find his name tagged in a few statuses. He then comes clean, swears they never slept together that they just talked and she worked at a place he would go and get lunch.He lied to me so many times... She says they slept together he says they didn't. I don't know if she just wants him and is trying to get me to believe he had sex with her so I would leave. I don't know what to believe. They didn't start talking until December so I know her baby is not his. But the things that run through my mind I have realizations like that's where he was that one time and when we are intimate I find myself thinking was he with her? I don't know who to believe because our sex life was fine it didn't slow down or stop, why would he need to go somewhere else? I asked him why would he do this to me? What did I do to deserve this? He had no answer.. He got comfortable with me and took me for granted....He got bored and wanted some excitement. I am trying so hard to forgive him our baby girl is due here in the next week. I have no where else to turn but the internet. I didn't want to post my business on Facebook too many fake friends on there I don't believe in airing my laundry for people I know to rumor about. I have no where else to turn I want to know what others would do or have done I know each situation is unique. I love him but the thoughts hurt and stupid things remind me. I'm not kind of person to throw your mistakes in your face constantly. How do I deal with this?