Ladies advice please?!

AF is over a week late. I took 3 tests all negative (last week) I been feeling extremely tired and have no appetite. Today I woke up and had dark red blood on my panties. After cleaning up, I returned to the bathroom about an hour later to pee and there was hardly any blood. Another hour or so later, there was light pink/brown on the tissue. Any thoughts what this could be? Anyone else experience this?