Clearblue Digital OPK

My period lasted from July 10-July 15. I started tracking my ovulation (first time) using the clearblue digital opk on cycle day 8, which was yesterday. It came up with the blank circle, so not a fertile day. Took one this morning and I got the flashy smiley face, telling me I’m entering my fertile week. I feel like that’s early to ovulate after a period. Anyone else ovulate early? Glow is telling me that I’ll ovulate on Saturday. Usually Glow is off by a day, but still pretty close.