In my own marriage, before we even got together I told him I wanted kids. My previous boyfriend of 3 years broke up with me saying he decided he never wanted kids and I didn't want any sort of confusion with a new guy. When our daughter was 4ish, my husband told me he thought he never wanted to have more kids. I cried for about an hour, and apparently sounded like my heart was breaking, which it was. We had previously agreed to three, and having him spring that on me was terrible. We ended up having a frank discussion into the night that involved him saying everything was going great with the one, why risk it with another when he wasn't sure he could love it as much (a common fear for dads, I think) and me saying that if he was serious he needed to tell me now because I wasn't going to waste the rest of my childbearing years on him. We laid out what we wanted to do before having a baby financially (paying off bills, etc) and 2 years later I've got a much better paying job with benefits that include a partially paid maternity leave (didn't have that before, will definitely help!) we've paid off the car and most of the credit card, and are finally trying to have another baby. He's still kind of scared, but less than he was when we first discussed it, and we've agreed that the 2nd will be our last and he'll get a vasectomy after the baby is born.
If we'd never had that discussion, I'm not sure where we'd be right now, marriage wise. Right now I feel the happiest in my marriage that I've ever been, and he's mentioned that I'm a lot more touchy feeley than I usually am, but knowing that we're on the same page and there's nothing hidden really makes me happy. Had he never said anything, just continued to not want another baby or help me work towards being able to afford it, I think I would have quietly resented him until I couldn't take it anymore and left.
You and your husband need to talk. Why do you want another baby? Do you feel your family is incomplete, or do you just want a baby to cuddle because they're cute and snuggly? Can you afford it? What are your husband's reasons for not wanting more? These are things you can only talk about and work out with him. Good luck.