I Have A Regulate Cycle Of 24-25 Days. Five Days

I have a regulate cycle of 24-25 days. Five days ago in cycle day 21 I have had unprotected sex(four days until my period was suppose to come). After 14 hours I took an Escapelle. I have to mention that my period is never late,but now it is. Should I be scared? Is there any chance my ovulation can happen durring the 21st day of my period. Thank you very much. I am looking forward to hearing from you.