Success with Letrozole after failed clomid?

Michaela • I'm 25, Married, PCOS, Two angle babies, Delivered our twins 7/25/17 at 24 weeks and they are perfect 💙💙
I am on my 3rd day of the first round of letrozole. My doc went ahead and put me on the 5mg instead of starting at 2.5 because I previously did 3 rounds of Clomid at 50mg, 100mg, and a 150mg and neither dose made me ovulate. Has anyone had success with Letrozole when clomid didn't even make you ovulate?