He doesn't want to..

I've been with my boyfriend for 7 years this year. I had a miscarriage on January 8th.. and I've been having a lot of problems trying to deal with it. So I finally came to terms with it and I'm doing better. But the only problem is, I want to try again. But my boyfriend doesn't want to.. he's all into car stuff right now. How in the hell do I try to talk to him about this. I really want to try again but he wants to "make racecar" right now.. it's heartbreaking.. help!