What’s wrong with me ?

last month October I had one day of spotting no period negative tests today November 9th I woke up normally nothing unusual around 10 am I got bad cramps severely bad I went to the bathroom and I had a small red black blood cloth with heavy red bleeding for about 30 minutes and I thought it was my period coming early I usually get them around the 14th but now it’s gone and I no longer have bleeding at all no pain no blood any idea what’s going on ?