Why Am I Not Getting Periods Even After Taking Sysron-N?

Hi My case as below Abortion of 1 month old unwanted pregnancy--0n 5th July2015 with the help of pills given by a doctor. After taking the pills, Doctor checked repeatedly 2-3 times and did Ultrasound to understand the cleaning process of Uterus. It was all clean. Only one minor cyst of 3cm was observed. Doctor said that the natural mensuration period will occur any time between 5th to 7th Aug2015. Doctor also said that if the period doesn t happen till 7th then take pill SYSRON-N 5mg two times a day for 3 days. I took it for 3 days but still my periods are not back. pl suggest.