Walgreens OPK - false positives?

Has anyone else gotten false positives from Walgreens OPKs? So far I used them to detect my ovulation, but then a week later I've gotten five positives in a row, and they are starkly positive (with the test line very much darker than the control). I heard that this brand is notorious for false positives but wanted to hear from you all to see if that rumor is justified. Is this just me?