Hubby unsure...any help appreciated!

Okay. So here's the deal. SO and I have been together for a little over 9 years, married for a little over 2 (started dating in high school). We had talked about it early on and he ALWAYS knew kids were a part of what I wanted out of life. He said he did too. We talked and decided when we would start. Time came around and he wanted to push it back, said he wasn't ready yet. Time came and he wanted to push it back again, and we talked and somewhere along the lines he decided he didn't kids (as a side note and added backstory-my sister went to jail for 4 months and I took two of her kids and they have been with us for almost 11 months). I'm not sure if it was taking my sisters kids or what happened. So we've talked and mostly argued about it. I'm so heartbroken and hurt but he said he would be fine with having at least one child for me, because I want it so badly. He doesn't think he will feel differently once we actually have a baby, but I know him and I know he will see the world differently. I'm not sure if he's worried about being a bad dad but the way he is with my nieces and with his cousins I know he's going to be. Our only other options would be to separate which neither of us wants, or for me to never have kids and try and find a way to live with it. He thinks that I'll grow to hate him if I never have a family but I don't want to feel like I forced him into this and have him resent me and our child. He tells me I'm not forcing him, and that all that matters to him is my happiness.

Any ladies out there have their SO unsure at first and then do a 180 once baby arrived? Or anyone have advice on how we should proceed? Currently in our 2nd month TTC. He's 24 and I'm 25 ❤✌❤✌