Ovulation confusion

Hello.

I started testing from Day 8 of my cycle - on day 10 I got a dark line whereas the app shows me I’m meant to ‘ovulate’ today (Day 16). I test all my cycles and this is the first time my ovulation is not matching up at all.

My last period cycle I was late by 3 days however negative for pregnancy.

I’m confused as to why this happened and what may have caused it.

Today is meant to be the day of ovulation however my lines are faint, almost not there.

Any help is appreciated