This is my third cycle on Letrozole. I have PCOS which I know can skew an OPK but I have never had a positive in over 6 months so I am hoping this might be a sign. My cycle started on 4/28 and I did 2 rounds of letrozole (stair step starting with 2.5mg and then up to 5.0mg)with a follicle check after each. Both checks showed nothing. I decided to try 7.5mg and I finished that last night. I woke up this morning and took an OPK and got this! I also noticed an increase in my CM today. Could this really be happening !?!?!?