I'm pushing him away..

I don't know what to do. My last husband really damaged me, he cheated often and made me feel like shit all the time. The person I've been with for the past 9 months also has a history of cheating on his ex wife. He's never given me anything to show he has cheated on me but I constantly ask him if he has or I find silly things to question him about. I don't know how to change this thinking, I'm pregnant with his baby and I'm either going to push him away or I am going to push him to cheat. How do I stop this thinking?