Hi, I Had My Periods On 18th Feb 2016. Needed

Hi, I had my periods on 18th feb 2016. Needed to postpone it in march, so started taking primolut n (one tablet daily) on 16th march and wanted to continue till 26th march for safekeeping the dates in april. But period happened on 22nd march (though i took tablet ). Now i have stopped taking tablets. Will my period be on the same date next month 1.e april? or next month also i need to take tablets? If yes... what doses and when?