Does I Pill Cause Delayed Periods?

HI. I M 23 YEAR GIRL FROM MUMBAI. I HV TAKEN I PILL AFTER PROTECTED SEX ON 22.01.2011 AS MY PARTNER WAS NOT CONFIDENT. BEFORE DAT MY PERIODS WERE ON 03.01.2011. I GOT AGAIN PERIOD IN SAME MONTH ON 24.01.2011, BUT IT WAS ONLY FOR 3 DAYS. THEN AFTER DAT I HAD PROTECTED SEX ON 20.02.2011. TILL NOW 23.03.2011 I HAVE NOT GOT MY PERIODS??? PLS HELP AND ANSWER MY QUERY... IS IT A I PILL SIDE EFFECTS ON MY PERIODS????