I usually have my periods on 6th (+/- 2)of every month.but this month i had ipill on 20th. so wen shld i get my periods if i am nt pregnant?

Common complaint: Irregular periods are one of the most common problems obgyns treat. If this is one time problem it usually resolves on its own. If this is a recurring problem you should be evaluated. Infections ; hormonal changes can cause spotting. If there is a concern for pregnancy then do a home pregnancy test . There are many options available to help regulate the menstrual cycle. Schedule a visit.