What’s happening with ovulation?

Ke

I use clear blue digital and for the last 4 days I’ve had only high readings, not peak, and before that low. Usually i only take a couple of tests in the fertile week and get 1 or 2 low then my peak. The ovulation date on this pic is my predicted. Any ideas what is happening? Usually regular as clockwork with everything but was 2 days late with AF last month, not sure if that has anything to do with it! Thanks 😊