To tired for sex

Hey guys so my boyfriend and I have been trying to conceive the past couple months. He is the one who brought it up to start trying and everything. But when it comes down to actually having sex he is always to tired. I don’t know what to do he has made it very clear he wants a baby. Haha I’m not a crazy bitch pushing it on him or anything lol. He does work long hours and has an exhausting job I just hate that he never wants to have sex I need some advice I have tried everything. We might have sex 3 times a month if that.