Dear Dr. I Had Unprotected Sex With My Partner Exactly

Dear Dr. I had unprotected sex with my partner exactly on the 14th day of my cycle and suspect I was ovulating and took postinor2 the next morning. 2 days later again we met and also took postinor2 the day that followed. About a week later I had a little blood that lasted not more that 2hrs but have not seen my period in 3 weeks after the intercourse. is there a possibility of preganancy because I feel my nipples are painful? help