OPK confusion

So I didn't realise that these opk test were a comparison. (Was expecting just one day of positive!) now I get that it's more about waiting for the darkest line possible... so, My tests have shown a faint line all week. Now I am 2 days past my predicted ovulation date and I'm still getting positive opks - this one today is probably slightly darker than they have been (maybe just because it's fresh?!). Also my bbt all over the place...

Have I still not ovulated? Did my body just not release an egg this month, or is my glow prediction just out?