Hi Doctor, Always My Periods Late For 4days This Tym

hi doctor, always my periods late for 4days this tym it came earlier(2 days before ). i have taken duphaston for 10 days.After taking it on the 17th day a red spot with discharge came, on next day less bleeding with dark red clott, then nxt day after evening it stopped. last march 28 my date then this tym aprl 26 why and only last for 2 days.