I want to prospone my period for 3 days. which is due on day after tomorrow. so which medicine should i take and from how many days before date?

Sorry, too late: I know of only one medicine that is known to do this, the synthetic progestin norethisterone. However, all of the authorities say you need to start it 3-4 days before your period is due, so if it is due in 2 days this will not work. And, like most meds, there can be serious side effects. See http://voices.Yahoo.Com/how-postpone-period-until-after-honeymoon-5981544.Html.