I want another baby... Husband says he is done :(

I want another baby... But Husband says he is done :(

​It breaks my heart that he doesnt want anymore kids. We always talked about having 4 kids. We have 2 now and i really want at least one more.  We can afford it and we are both great parents who love their kids. I don't see why we have to stop at 2! 
​Any advice??? 
​I'm secretly hoping to get pregnant. Lol