There can be mild pain but subsides after a few days. You haven't provided any X-ray so can't comment on the quality of the root canal . Usually there will be a dull ache for a period of two to three days ( not in all patients ) which will reduce once you take A pain killer . Consult with the dentist who performed the root canal. If the pain doesn't subside , an X-ray has to be done to find out the cause . If your dentist has already prescribed painkillers you can take them . If not take an Imol plus for Now and see The dentist as early as possible . RooT canal can be redone if necessary after seeing the X-ray .Get a second opinion if needed (only if the dentist who performed it doesn't provide a remedy).