Sex all the time but no baby

Hi! First time writing a blog, or whatever you call this lol. My fiancé and I have sex all the time. Like every other day, yet no baby. Starting to get discouraged and think it'll never happen for me. Any encouragement or anything I can do? I have PCOS and am on Metformin. He has 3 kids from a previous marriage so he's good in that department, lol. I'm 27 so if it don't happen soon I'm afraid it never will. I was with a guy prior to this relationship for 4 years and there was never a hint to possibly being pregnant.