Suggest Cause And Remedy For Incredibly Heavy Periods

For the last six months I ve had incredibly heavy periods, going through at least 2 pads an hour and cramps forcing me away from school. I got my first period four years ago, so I know what is abnormal for me. Accompanied with this is random spotting, for lack of a better word, no cramps or headache. It starts about a week after my period and only lasts a few hours. My question is, do I need to see a doctor? My grandmother says I should and to go on birth control, but my mother disagrees.