Ovulation day keeps moving


Every day my ovulation day is moving on the calendar. I am now at 9 clear blue advanced kits sticks and started on cd8 and it still says low fertility. Why does my Ovulation day keep moving on the app? And I’m using my first urine after I wake up. I feel like I’m still doing something wrong... ? At this rate I should have already ovulated and be getting my period next week.