Does glow change my O date when I log my period??

Samantha • After 2 years of heartache and 1 miscarriage we welcomed our baby girl on 8/31/20 💗🌈

I was looking back at my previous months logs and every single month I get my period exactly 2 weeks after what glow has as my O date... But my cycles vary from 26-31 days. So does glow just move the O date when I log the first day of my period?