Honest advice needed.

My husband have I have been married for less than a year and he is constantly excusing me of cheating on him. He's a truck driver and is gone for 1-3 weeks at a time which doesn't help his insecurities. He told me it's because the last few girlfriends he had cheated on him and now has a hard time believing that I won't hurt him. Well I found out recently from his dad that it's not true, and that they left because of him always accusing them of cheating. He told me he walked in on his ex with another guy in his condo, we'll come to find out he never had a condo and that they lived with his dad and she never cheated on him. That after their son was born(which he also lied about actually being in a relationship with her when he was born and how he was concieved) if she didn't answer her phone he would call the house and harass his stepmother about other guys being there and how she was lieing to him...... There's a lot more iv found out from talking to different people in his family and I'm not sure who I married anymore. I know things are in his past but that fact he's lied to me isn't setting well with me and if I try to confront him hell deny it and accuse them of trying to ruin our marriage. I don't know what to do any more and everyone iv tryed to talk to about it has just said I need to really think about it, but I'm 22 weeks pregnant and my emotions are all over the place and I don't want to make a decision just biased on emotion. Any advice is welcome , thank you in advance.