Can Plan B Pill Disrupt Menstrual Cycle?

i took the plan b pill in july, i had a normal period when expected about a week later, but then i completley skiped my next period for september, i started a normal period on october 12th, then for the month of november i skiped my period again. Now on december 3rd i just started to have like a brown discharge, only when i wipe, and its not very much. Could the plan b pill really have messed my cycle up?