I have a quick question for you ladies. It's time to start OPK's for this cycle, and I wanted your opinion. I had always been told that you should use afternoon urine for OPKs, but my RE recommends using FMU if you are having IUI done. I am just using Clomid this cycle....no IUI, but I wondered what was the best thing to do. Should I use afternoon urine (I might not be able to test at the same time every day either) or should I use FMU? What's your opinion?