why ami having a period that is going into it's 4th week?

period for 3 weeks presently and still continuing. hi, my name is Lina, i have been having my period for 3 weeks. sometimes it was heavy, other times it was light. i also realized that it was sometimes darker (rust red/brown) at times and it carried an unusual odor at times. could you please tell me what may be the possibilities of what is happening to me? i won't stop bleeding. then 2hours ago, a massive clot of blood came out, it fit into the palm of my hand