Not uncommon. Postoperative infection complication after tooth extraction is not uncommon. To avoid complications, the patient has to maintain good oral hygiene and should avoid smoking and drinking alcohol. To treat infections, antibiotics are given by the dentist and tissue curettage is possible.
Leave the area alone. After an extraction, creating turbulence in your mouth will delay the blood clot formation. Prolonged bleeding will set you up for a greater risk of complication. The abscess will resolve on its own if the source of the infection has been removed. If the infection was severe enough and especially if you have a medical condition that could impair your immune system, antibiotics may be indicated.
It Will heal. Just keep the extraction wound clean and take good care of your oral hygiene. It usually heals uneventfully.