Why Am I Having Heavy Period For 12 Days?

HI THERE DOCTOR I AM 25 HAVE A SON OF 18 MONTHS AND I AM ON NORDETTE CONTRASEPTIVE. MY PERIOD STARTED 12 DAYS BACK HAD THE NORMAL 5 DAYS BLEEDING BUT YESTERDAY STARTED BLEEDING HEAVY GOING THROUGH 6-8 PADS DAILY NOT SURE WHAT TO DO I HAVE PERIOD PAID REAL BAD AS WELL IS THIS THE NORDETTE OR SOMETHING ELSE