Hi. I Took A Contraceptive Pill Two Days After I

Hi. I took a contraceptive pill two days after i had unprotected sex but he pulled out before ejaculating. Yesterday my second day of the pill I had a bleeding, very light and very weak. Today is my third day and I have a red blood like my normal menstruation but its not heavy. Days before I took the pill I had pms and before I got my period the second day I took a pregnancy test and it came out negative. Can I be pregnant? Can I stop taking my third pill? Please help. :(