How to deal with baby fever?

I've got a good man in my life at least 2.5K a month who wants to make me his wife. We've both got our futures set out for us and good insurance and all that but we aren't even twenty yet and I can't shake the images of what our children would look/be like and dear Lord I want a family with this dude. My sister in law had my niece just seven months ago but now we live five hours apart; having my niece around helped thwart the baby fever because I had a baby to dote on and long nights/stinky diapers to remind why I'm not mentally prepared yet.

Now I don't have baby girl nearby and can't stop my brain from saying, "Make one!"

I truly believe I found my soulmate and he's a good enough guy that he wouldn't let us rush into something as big as having a child too soon. But how do I stop wanting one so badly? It's driving me nuts!