How many IUI attempts w/ unexplained infertility?

IUI attempts w/ unexplained infertility?" />
My husband and I have unexplained infertility. All tests come back normal and his sperm results were passing with flying colors. Doctor said last attempt is IUI and 3 attempts then he will push me forward to an IVF doctor. 
Anyone else with unexplained infertility have this work? How many insemenations did you go through before you were pregnant ? 

Vote below to see results!