Trying to get pregnant

My fiancé and I have been trying for a couple months now he keeps saying he can’t have kids but there is no proof we had a miscarriage in July and he don’t believe it still we have tried everything and he talks about a baby and it hurts me and when u talk about it it hurts him and makes him angery idk what to do we have two kids due to my ex relationship and he has stepped up to be the dad bc there dad ain’t there or tries to be hes a amazing dad I just want one of are own please help