I want to be a mom

I am currently going through a divorce, it’s not messy but the reason behind it is a big deal for me. I want to be a mom and my ex never wants children, I’m 31 and after being married for seven years I never had a pregnancy scare.. now this may make me sound like I’m rushing things, but I am in a new relationship with a man who has a child and wants more! Only problem is, my body rejects and I end up having pregnancy symptoms and then I start my period. I’m giving up hope, all I want is to be a mom.