Period for long time?!?!?!?!?

i have had my period for about a year and a half and i missed my period last month. i have only missed my period one other month. now i have my period and it is unusually heavy and i have had it for nine days. i usually only have it for four days. i go through a super plus tampon in about 2 hours. i usually can barely fill up a regular one. please help soon!!!