I Took The Generic Form Of The Plan B Pill

I took the generic form of the plan b pill and I had unpertected sex on the 29th of June still haven’t gotten my period. My periods were never regular to begin with due to I was on the depo for 3 years prior to me getting off of it never was regular ever some months never got it at all !!! But didn’t know if the plan b will prolong my period even longer ?? Or I need to get pregnancy test