Help !!!!!!

Sooo my last period ended November 21st. And I haven't had a period since. Towards the end of December I started spotting here and there. As I would wipe, then there would be light color red blood but it would stop for 2 days. Then January 1st, I had a small blood clot. I haven't bled since. All my hpt tests are negative. I've been cramping non stop but not too extreme, just annoying cramping.