I had unprotected sex on November 3rd which was the last day of my period and it was like around 12:00pm and took plan b on November 4th like around 2:30pm. My partner did cum inside of me. Six days later I had a brown discharge with little of red blood that lasted 3 days. My expected period is November 29 and I am 4 days late. I don't have any pregnancy symptoms just that my back is hurting the upper part and sometimes I burp with a little amount of mouth throw up. Was that my period? Could I be pregnant? I'm really scared, I've been worrying about this a lot!