Something is messed up

I'm currently 10 days late. Negative blood and urine tests at 6 days late. No idea when I ovulated as at CD 20 I stopped testing with not even a faint line.

Normally the day before a positive I'll finally see SOMETHING. Before and after though it's either completely white or almost not even there. However, the last couple days, for shits and giggles, I checked and it's the same darkness (about "halfway there" I'd say) as the day before ovulation. I have an appointment next Wednesday with my gyno but what the hell could be going on?! I've never been this late before. Only a day or two. Someone please offer some sort of suggestion or reassurance.