hi , i am due my period on the 6th august ,and will be due on my period when i go on holiday in september. ihave got norethisterone perscribed by my Dr but wondered if i take it 3 days before my period in august, then start bleeding 2-3 days when i finish taking it, will it be 28 days till my next period in september ,as i dont really want to be taking tablets while im on holiday, as i forget to take them