Baby fever depression

Recently my fiance and I had a pregnancy scare which turned out to be negative. It got me thinking and it turns out I really want to have a baby but my fiance doesn't he says he isn't ready to be a father. I respect that and I want him to want to have a baby as much as me so I agreed to wait until he was ready. Now every time I see a post on social media about one of my friends finding out they are pregnant and posting pictures of their kids it makes me so sad cause I want to start a family with the love of my life but I also respect my fiance's wishes to wait until he's ready. I just don't know what to do I've tried talking to my fiance about it but he said he isn't ready to be a father and that he was sorry I was feeling this way. I just don't know what to do is driving me crazy.