What are my chances of getting pregnant?

I had sex with my boyfriend on the first day of my period (29th Aug). Everything happened to fast so he ejaculated inside me for the first time. Took the morning after pill about 48 hours later. I have a regular cycle (usually about 27-29days). My period ended on 3rd Sept. Today, there was some light blood when I clean my vagina + there were some stains on my panty liner. What the chances of me getting pregnant? I'm feeling super paranoid right now :/ I've still been feeling crampy but I suspect it's the side effects of taking the morning after pill. Please reply me ASAP, someone :(