Day 3 still old blood TMI

Theirs still brownish/black blood along w some regular period blood. My period was 16 days late didn’t get one all February. Took another test last night and it was negative. Would like to mention my flow overall has been light/moderate except for yesterday evening it picked up but still not enough to fill a tampon. But it has slowed down a bunch and now looks like the way it did yesterday. Also I spotted brown blood a good 5 days before this cycle too. (PIC FROM YESTERDAY ) I’ve had a bunch of brown blood this cycle still. What could be going on?