Anyone have any tips

My fiancé and I have been trying to get pregnant for over two years. I've tried three cycles of clomid, I have a cycle every 29 to 31 days, I just started Metfotmin, I am doing the ovulation testing and I am ovulating every month, we have sex every other day, he is 25 and has been tested within normal limits on a sperm count. I've already had two pregnancies with my previous marriage. The doctor says we are having a hard time due to an IUD that I took out two years ago. I did not have a cycle for two years. But they have been very regular for the past 25 months.