I was on letrozole 2.5mg and then tried 5mg along with metformin and provera to bring on AF with no success on ovulating. My progesterone levels were really low. My doctor is now switching me from letrozole to Clomid 100mg. I've heard many success stories going from clomid to letrozole but not sure about vice versa. Has anyone switched to clomid after letrozole and had success? Hopefully this will be just what I need!