Complete transformatory dose of Primolut N is 120-150 mg. To get this dose, one tablet three times a day for 10 days is recommended and tablet taking is started 3 days before expected date of periods for maximum 10 days. You can not take this medicine for longer duration because it can cause hypertransformation of endometrium which can lead to amenorrhea and then D & C is required. You have taken incorrect dose of Primolut N because it is not indicated to use one tablet in any indication. Primolut N is not indicated to postpone periods for 15 days. You can only postpone for 10 days to avoid any complication.