No lines at all on opk?

Li

Hi all! I’ve been using clear blue non-digital ovulation kit and I started testing in the AM on the day my period stopped. It’s our first time TTC. Im still testing 1x first thing in the AM. The first two days I had negative tests. The following two days I’ve peed on the OPK strip, there have been no lines whatsoever....not even a control/reference line. Yesterday I thought maybe I hadn’t peed enough, so today I held it in the stream longer than 5 seconds and still-same result. i’m going to the store to buy additional OPKs later, so idk if I should get digital or what.

Did I get a bum kit or what am I doing incorrectly?

Thanks for your insight!