Has anyone ever taken Letrozole after Clomid failed?

Michaela • I'm 25, Married, PCOS, Two angle babies, Delivered our twins 7/25/17 at 24 weeks and they are perfect 💙💙

A little background: I have PCOS, I do not ovulate on my own, I do not have a period without taking provera, have done 3 rounds of Clomid with no success. Doctor and I decided to try letrozole next month before going to an RE.

Looking for experiences with Letrozole after Clomid didn't work for you. Any advice/experiences offered appreciated.