OPK lines getting lighter

Tee

I’ve been trying to see when I ovulate and have done a test each day since 1st but they seem to be getting lighter lines? I’ve been testing the same time each day the only difference is the last 2 days I wasn’t able to hold my pee for as long. Surely I can’t of ovulated straight after my period? I’m completely new to <a href="https://play.google.com/store/apps/details?id=com.glow.android">tracking ovulation</a>