Suggest Treatment For Heavy Vaginal Bleeding During Menstruation

I was a week late for my period. I thought that i was pregnant because it was a definite possiblity. Finally i got my period, but it's not a regular period. Usually in the first couple days i would have to change my tampon once every 5-6 hours and now i cannot go an hour without having to change it. its SUPER HEAVY and its never been like this before. and its somewhat more clotty than usual.