How to slow down the baby talk?

My boyfriend and I have talked about kids and he wants to wait until age 30 but said he's willing to negotiate after we get settled in a home of our own but every time I see my best friend and her baby my baby fever comes back and drives me crazy because I keep bringing it up to him but I don't want to push it too far and push him away we are only 23 and still have some growing up to do how do I slow myself down ?