Ovulation

Elizabeth
On Glow it says I ovulated on the 10th. I ovulated on the 9th. It also says 29.9% on the 9th and 19.9% on the 10th. I'm guessing the percentage means how much of a chance you get pregnant, right? Glow says I'm 9 dpo, but in reality I should be 10 dpo. So confused!