Birth control “urgent”

Patient: I went to the doctor on thursday the 1st and was prescribed to birth control and to start taking it today because i had my period from the 23-28 so i was doing the sunday start. i just got my period again yesterday the 4th and i was thinking its because i took plan b on saturday the 26th i don’t know if i should take it today while i have already am having my period or wait till its over. my doctor does not know i just got my period yesterday because she is not in the office