Late period negative hpt light bleeding brown discharge and cramps. Please help !!?

I am experimenting something different that has never happened to me. I usually have irregular periods but no more then 1 month. And this time it has been since February since I haven't had a period. I've token in between 6 hpt, all negative. To the point that I just left it alone til Monday night that I realized when I went to the restroom to wipe I noticed light bleeding so I figured I would be starting my period so I put a pad on. I'm the mourning when I woke up I noticed that there was nothing. I only see light bleeding when I wipe. And now I'm see a brown discharge. What could it be if all my hpt say negative ??? Please help