Clomid and OPKs

I have PCOS and my doc put me on clomid 50 mg for CD 5 to 9 it's my 2nd time trying it and the 1st time I'm not sure if I even ovulated... my doc told me to try the clear blue opk and I did but it only showed "High" but never a peak...this time I am tracking my bbt, CM, and using the opk.... anyone else have experience using clear blue opk? Should I try something else or stick to it? Or should I make an appointment with my doc so she can do a blood test to see if I ovulated this time?