Clearblue Advanced Ovulation Sticks

So according to Glow I ovulated on Sunday the 21st. But I know that can be a little off so I have been using Clearblue Advanced ovulation sticks to see what’s up.

Since Tuesday the 16th and every day since I’ve gotten the HIGH back. Is that normal to have 7 days of being in high fertility mode? I’m so confused. I thought by now I would have hit the PEAK day on those sticks.