I think my bf has a breeding/impregnating kink and I hate it

M23 & F23 (me) I think he is slowly crossing the line between regular dirty talk and actually meaning the things he’s saying and it has started to really bother me. During sex he says “I wanna *** deep inside you” and similar things like that which is pretty regular, but now it has escalated to “your uterus is mine” not “your p**** is mine” like he used to which is not crossing the line quite yet, but to say “uterus” makes me really uncomfortable.

Another thing is that we agreed he would never *** inside of me because of my paranoia and one time during sex a while ago we were dirty talking and I said “*** inside of me” but not really wanting him to, and he did and I had to take a plan b. That was a while ago but now I think it has made him have that kink. Also with this trump presidency coming up it crosses the line for me when he tries to claim my body like that. The kink in general is wanting to dominate a woman’s body and I don’t want any part of that. He also is always is telling me how cute I would be if I was pregnant and also wants to know what phase of my cycle I’m on. At first it was kinda funny but he says it so much that it has gotten to be too much for me

I’ve had a conversation about it with him but I don’t think he takes me seriously and I need to set this boundary. I feel like next time he says something like that I need to set a boundary right then and there but I don’t have any ideas, but like in a positive reinforcement (i think) type of way.