Starting Femara/Letrozole 2.5 tomorrow

Hannah
This is my first Letrozole cycle, I start 2.5 mg days 3-7 (tomorrow is day 3) I had 3 non-responsive rounds of Clomid 50, 100, 100.  Has anyone else gone through this? I'm also on Metformin 500mg twice a day for my PCOS. Hoping to be finished with all of these pills soon! Has anyone had their BFP on this dosage of Letrozole?