When is a heavy flow NO longer considered normal?

@ about 3pm yest i bought a 18pack of super plus tampons & im now down to 4. Its 8am now ive also had to use an all nighter pad. & have had to change my clothes 4 times. Its litteraly just flowing. The tampon is doing NOTHING. Its so heavy that my tampon is falling out by its self without me having to take it out. As far as time from im thinking about an hour tops before i have to run to the bathroom and change it. & there its already gone threw.