TMI Blood clot? Or miscarriage? Help pleasee!!!

Before all this happened 2 days ago i was spotting light pinkish and today this is the first time, this happens ive never seen something that big, im 5 days late on my period and i took a pregnancy test yesterday came out negative. Today as i was laying down on the couch, i felt something gushing down, i started feeling cramps and i could barely walk when My husband helped me walk to the bathroom as soon as i sat down i felt something come out of me, and idk what this is.

It looks smaller in picture but it was about the size of my thumb. And after i got in the shower and laid in bed and theres no sign of any blood or anything. Has this happened to someone?