Is It Possible To Get Pregnant Despite Having Postinor 2 Post Unprotected Sex?

Hi doctor I had sex on 19th of last mnth n i was ovulating tho we used withdrawal method bt took p2 before 48 hrs are over my cycle is 26-28 days now am having breast tenderness n a feeling lyk am having periods my question is there any possibility that i mit be pregnant or the p2 is the one causing the delay.