..Im Currently Taking Norethindrone And My Doctor Instructed For Three

..Im currently taking norethindrone and my doctor instructed for three months to not take the placebo week and on the fourth month take the placebo week. I thought norethindrone only had active pills and no placebo week. What is the point of not taking the last week for three months and going to next pack? Is it a waste to throw away three weeks of pills? I am also taking 100 mg of topiramte twice a day for migraines with aura and seizures.