Hi.. Welcome to HEALTHCARE MAGIC.. I have gone through your query and can understand your concern... As per your complain a bump over the gums at the site of healing Socket after three weeks of extraction is not a normal finding and it is a sign of infection in that area leading to pus formation and appearance of a bump.. However it can also be due to Hematoma formation that occurs due to severing of blood vessels at the time of xtraction leading to accumulation of blood into the soft tissues and forming a lump.. You should immediately consult a dentist and if there is abscess formation due to infection then the dentist can do Scaling in that area to remove infection and also advise you to take antibiotics for complete elimination of infection.. He can also take an x Ray to rule out any remaining foreign body or tooth piece and if anything is present removal of same can resolve the lump.. Hope this information helps.. Regards.