What Should I Do If My Period Is Delayed After Taking An I-pill, And I Ve Experienced Random Lower Abdominal Pain?

Hi, I had unprotected sex on january 8th and took an ipill on january 11th within 72 hours. My period was due on january 15th but neither have i had my period nor any withdrawal bleeding or spotting till today. But i have been experiencing random lower abdominal pain sometimes. What should I do?Please suggest.