What Causes Missed Period After Taking Primolut N?

Hi, My last period was on 3rd February.. But this time still I didn t get my period..is there a chances of pregnancy? On January I had taken premolitn tablet to postpone my periods..is this a reason for not getting the period.. Me and my husband had oral sex..but he didn t leave the sperm..is there a chance of getting pregnant? Please help me..I am worried..