am I insane for wanting to get pregnant?

My boyfriend and I have been together for four years. I'm 22 and he's 34 so there's obviously an age gap here. I know he has time biologically, but I don't want to wait until he's like 40 to start a family. We've lived together for the last two years. I know I'm young, but I've a career and am financially stable enough to have a child. He's secure in a career as well so it can't be finances. My boyfriend actively talks about having children with me but never wants to get down to it and plan it out. I'm getting to the point where I don't feel like it's ever going to happen with him, and am starting to resent him. Am I insane? It's causing so much tension in our relationship. I don't even want to have sex anymore because the thought of him pulling out seriously hurts my feelings.