Letrozole and PCOS success?

Day 1 of Letrozole. 2.5mg....any success with that dose? I’m afraid that the dose is too small?

Has anyone taken 5mg for 3 days instead of 2.5 for 5 days?

Also with PCOS periods aren’t normal so can anyone tell me what day they ovulated on? I know it depends from person to person... my periods right now are every 60 days or so. Never the same every cycle...