I was about 6 days late for my cycle when I noticed dark brown spotting. This was 3 days ago and yesterday I started my cycle, along with full cramping from legs to back to lower abdomen . The cramps were almost unbearable, and I was bleeding extremely heavy. Today im lighter than even a normal period and I seem to be havimg heartburn , it is currently keeping me from sleep. There is chance of pregancy, but test said negative. .. I am 21, just worried and confused!