You’re 37, he has all the time in the world to “try again” but you do not. You’ve told him you don’t want to terminate and it’s solely up to you what you do to your body. You’ve communicated “no”, and if he can’t listen you’re probably better off ending the relationship then waiting around for him to change his mind. There’s a point when asking becomes coercive and manipulative, please watch out for signs of him manipulating you. While compassionate towards his grieve I cannot fathom having a base understanding of human biology, which I’m assuming he has, and asking someone who more than likely won’t be able to safely conceive again, to terminate. He’s essentially asking you to give up your chance at motherhood and gamble with fate on whether or not you can get pregnant again with or without medical intervention. Despite what he’s going through this is your choice. Good luck OP.