What should I do?

Hey ladies I really just want your input. I don’t know what to do. I dated a guy from 12 years old until I was 20. Totally felt like this was the love of my life since day 1, couldn’t picture life without him. We were on and off but always ended up together. In our adult years we forgave each other for everything and tried moving forward, thing we’re going great until he got another women pregnant. It was too hard for me to handle so I left. Got myself together, and eventually met another guy a year later. Now I’m 25 and we’ve been together for 4 years and we’re engaged to be married in a few months and he is amazing and treats me wonderfully. But for the past month I’ve randomly been having frequent dreams about my ex that I literally wake up in tears. Crazy part is I haven’t thought of him in all the year I’ve been with my fiancé but I can’t seem to figure out why I keep having these dreams of me walking down the aisle and seeing him or me growing old and having children with him. I’ve cried a few times because I wake up feeling like idk what to do. Am I crazy? What would you do in my situation?