TMI/ Period or what?

So I go to Dr Thursday, but my period came yesterday, but something isn’t right. My bleeding starts then stops about the size of a golf ball is all I get on a pad, its mainly when I wipe & tiny clots are in it. Cramps are completely unbearable even taking something for them! Nausea don’t wanna eat( I’ve took pregnancy test all negative). Is this my period, or what’s going on? 😭 my period has NEVER been like this I had a baby almost 9 months ago!