Hormonal, insecure, losing it

So I am currently almost 6 months pregnant. I have been divorced for a few years and have two girls with my previous marriage. My bf and I have been dating for a year now and I’m pregnant. I had always told him I wanted to be in a good, healthy relationship and married before I ever had another baby. I don’t ever want to be single with another baby daddy. We seem to have shared similar dreams, wants, goals in life and he does seem to work towards a better future. And has said being with me, has made him think about his future and actually work towards goals. He dated someone a few years ago and she was pregnant and ended up going back to her ex and got an abortion. But he said they were looking at rings and what not. Why am I jealous and feel insecure he has not done that with me. I’m obviously not going to get an abortion. I want to trust he wants to marry me. He knew what I wanted and how I wanted to be married before we had a baby and obviously it didn’t work out that way which is fine. But it’s driving me crazy that he said he and his ex were looking at rings and he hasn’t even brought that up with me. He hasn’t brought anything up with me and i don’t want to say anything to him and sound crazy cause I already feel crazy. I just want to feel secure and not that a rig would mean it’ll work out cause anyone can call it quits at anytime. But I want to know he feels that way for me and I want him to bring it up. What if he never does? Or doesn’t see that road with us? Even though he said he sees it one day, but why are some people ok with having a baby and committing to that but not marriage? I have worked so hard to get my girls and I a house of our own, a good life. I was comfortable with just my girls and I. Then this happened and it scares the hell out of me. Being in a marriage where the guy had no aspirations, didn’t even fight to keep the girls and I in his life, now lives with his mom and shares a room with our girls when he has them, it’s frustrating and I don’t want to end up in another custody battle. I would never cheat and I have goals and I’m a strong independent woman but I need to know why he would look at rings with her but never bring that up with me.....