What Causes Delayed Menstruation After Taking Oral Contraceptive Before Intercourse?

In the months of January my hubby give me some medicine to stop pregnancy so I had and due to that blood flowed by Virginia. ..after then we had gone intercourse. ..but I haven't took any medicine. .yet now my period time is over yet it havent occur in this month...I had thought might be due to pregnancy but as I test via preganews it show one pink line...so my question is m I pregnant. ..