Plan b

Hi girls!!!! The other day I was having sex with my bf, we are always very careful, but this time the condom broke. ( I was on my fertile days). I took the plan b pill like 8 hours later. Exactly a week later I got my period for the normal time, it was just kinda brownish. I'm confused because I wasn't supposed to get it that day, it came almost two weeks earlier. This is my first time taking the plan b pill... was that normal? I'm not pregnant right ? Sorry if my question sounds dumb.