sex but he can't go....

It's weird really we have never really had issues when it came to my husband "finishing", let's start that we were trying for a year and we finally got pregnant in December only to find out in January that I had a miscarriage and lost the pregnancy. That was January 30th, we had sex two weeks after my miscarriage and everything was fine but we weren't trying bc we were waiting for my first AF to come so we could start again well she showed up march 1 and now everytime we have sex and we're suppose to be trying he can't finish it literally breaks my heart because I've / we've wanted a baby for so long I have felt pregnant and I miss it and I want to try but I can't do it alone. I don't make it a chore either where like we have to have sex to make a baby I don't put stress on him. Idk what's wrong. Any tips, opinions, experiences please share .