Suggest Remedy To Postpone Periods While On Triquilar

Hi ,By taking triquilar 21 day tablets i would get my periods on 8th of march, but i want to get my periods only by 18th of march.So should i continue with the third week tablets(day12-21)from a second pack of triquilar till 14th march,as soon as the first pack is over.Normally i get my periods after three days after finishing the pill.Please help me ..