TTC with fiancé....anyone else?

My fiancé and I got engaged in February. As soon as we decided to wait a few months to start any wedding planning, I realized we'll probably end up having our wedding summer of 2019. We've been together for 6 years, I'm 26 and he's 27. We're both doing well in our careers and are financially stable - we also both feel ready to have a baby together. I'm sure it makes sense to just wait until after marriage but I feel like if there's a possibility that it could take time and/or be a challenge - then we should just not prevent it and let it happen (with some extra BDing in the FW) This was our first month of really trying, and AF showed up on 4/25...Anyone else TTC with their fiancé? And why aren't you two waiting until after marriage to try?