My DH is 33, I'm 30. We started TTC in August (although he wouldn't admit it - I told him birth control was his department from that point on - he stopped using any). He only admitted we were trying after we had a miscarriage in March. Men are funny like that. He needed to be in control of the situation. I've always tried not to pressure him, but it took me putting it in his hands before we started trying to get pregnant. Now we're trying again and he will say it out loud, but if I try to initiate sex he's not in the mood. I think he feels like all I want are his spermies.
Talk with your BF and see if you can find out what he's feeling (I know, easier said than done) without pressuring him. He may be worried about supporting a family, raising his kids right, etc. Or he may just be too immature and really not ready. Whatever the case may be, be respectful of his wishes and be patient with him. You have a lot of child bearing years ahead of you.
I hope you find the answers you're looking for.
PS - DH and I dated for 5 1/2 years before we got married and waited 7 years after that to TTC - I picked a slow mover too, but he's worth the wait!