Anyone with IUI experience?

Melissa
After my 2nd MC in May, my dr put me on Letrozole with Progesterone & extra folic acid. Never got a BFP. So we switched back to 100mg of Clomid these past few months. Still nada. So now the discussion is onto IUI. What are your experiences with it? How does it all work? Cost? How many times did you have to do it before you got your BFP?  Thanks girls.