What’s going on with my period not period

So last month my “period” came a week early and it wasn’t a consistent period. It was VERY light spotting that I would only see whenever I wiped. This month I didn’t get my period. I keep taking tests and they come up negative. I even got blood work done that came back negative. I was in horrible pain on Monday which is exactly a week after I’m supposed to get my period. I had blood clots coming out almost all day and then just nothing. No cramps and no blood. I don’t understand what’s going on! My period always comes on the 24th. Every month.