Clear Blue Advanced OPK - Low to Peak?!

Hey y’all! I started using the CB Advanced OPK this cycle and I’m a little unsure if it’s giving me a false reading?? I started testing on CD 7 and got;

- ‘low’ for 3 days

- CD 11 ‘high’

- CD 12 got ‘high’ in the AM and then ‘Peak’ in the afternoon.

Is it normal to only have 1.5 days of ‘high’??