What Causes Heavy Vaginal Bleeding,nausea And Headache?

hi my name is onika...well at the begining of the month i started spotting brown blood i was cramping and throwing up like morning sickness.then it stopped last week it came back and i went to the e.r. they took some urine and said i had no ifections and i wasnt preganat they said it was period cramps..then i went back to the hospital they took blood and said the same thing 3 days ago i bleed really heavy then it stopped and now i feel naseua i cant hold anything down im having hot and cold flashes and i have a headache..but i also had my tubes tied almost 9 years ago can u help me and tell what might be wrong with me please