Out again...on to 3rd letrozole cycle

Need a pep talk if anyone is able...

First two cycles of letrozole I responded well with 2 mature follicles on my cd 12/13 scans. We BDed exactly when we were told to, and husband’s semen analysis is fantastic. If I ovulated both follicles we should have had double the chance of getting pregnant both of those cycles, and yet nope. I can’t help but fear there is something ELSE wrong with me! Besides the PCOS that put me on letrozole in the first place.

Feeling sad and worried. Thanks for your help.