OPKs and PCOS

I'm currently using Walgreens opk kit. The leaflet has a disclaimer about PCOS and how it could be wrong about predicting ovulation. I have PCOS and I'm a little concerned that I might miss my fertile window. I've been TTC since June 2015. I did have a positive last month on the 15th and BD'd that day and a few days before that too to no avail. Just wondering if any specific opk kit was helpful/correct for you if you have PCOS and are TTC.