Pls help!!

On July 16th I had an incident and I took plan b within 48 hours after. About a week later I got what I think was my period. It seemed to be a normal amount of blood and a normal color. Recently my boobs have been SO sore and my nipples are just different (pointier and maybe bigger?). I’ve been having cramps and I was supposed to get my period yesterday. I started spotting today but is that the start of my period or could it mean something else? I really really can’t be pregnant so I’m freaking out. Please give ur opinions!!