Fiancé doesn’t want children

My fiancé and I have been together 5 years on New Years, he has 11 year old twins from a previous relationship. Perfect relationship with ex etc, after a conversation today he’s basically told me he doesn’t want anymore children, this is after our first date where he asked me if I wanted kids, he’s 42 I’m 33. It’s not out of nowhere as he’s made comments this year like he’s getting too old etc but I brushed them off; I don’t know now what to do. The thought of not having children with the love of my life, seeing how much of an amazing dad he is to his boys just terrifies me. All of my friends are experiencing the excitement of having a baby for the first time, I’ll never experience that with my fiancé because he’s been there already, but knowing that he doesn’t want anymore kids

I don’t know what to do. If I stay I may one day regret not having children of my own, or resent the relationship the boys have with there dad knowing that I won’t have that. But if we do have a baby knowing he doesn’t actually want one and would only be doing it for me.

I know it will always have to be my decision but I don’t know who to talk to