Am I tripping?

My boyfriend proposed to me recently and though it has been something I’ve been waiting on I wasn’t ecstatic. I’m happy but then again I’m doubtful. In the beginning of our relationship he still had dealings with his ex. However we moved past that, I forgave him and he has literally done NOTHING for me question my trust towards him since then. Like I have nothing in me that believes he would cheat. However, I always planned to wait until marriage for sex. I was 4 years celibate before meeting him and those boundaries were broken early on in the relationship and I don’t even know how I let it happen, however I made the decision that I couldn’t continue to have sex and he was fine with it - though it’s not easy for him but a week after that decision I found out I was pregnant, and now I’m 15 weeks.

My biggest thing is I don’t know if I should marry him because of the boundaries, because of the fact that we didn’t wait until marriage - we are waiting now but I’m truly unsure because of the fact that it happened.

I’m adamant about improving my relationship with God and we just show it in two different ways. He truly treats me like a queen, and I know he will be a phenomenal dad but marriage is a big step and I don’t know if he’s the one I should make that big of a step with. I love him with everything in me and he is about to be the father of my child. But I don’t know if I’m too stuck on how I thought it should be or if it’s really not it. Outside of my whole ordeal of not waiting there’s no reason I wouldn’t believe he’s the one.