Confused?

Maddy • Wifey, dog mommy, Baby #1 on the way 4/20/16, been with my hubby for 8 years, married for 1!
I got the blinking smiley face today and yesterday on clear blue ovulation test- so I SHOULD get the peak ovulation smiley tomorrow and the next day which is when I should ovulate. But what I don't get is the app is saying my most fertile days are tomorrow 27% the 30th 33% and the 31st 22%. If I ovulate on the 30th, shouldn't the 31st be blue as in a low percentage of conceiving? Or is it still a fertile period for 24 hours after your ovulate?