Had cortisone shot injected into shoulder joint which wasn't sterilized. pain & stiffness now & wondering if infected? how would i know? i'm scared :(

Few symptoms: Pain and stiffness could be simply a manifestation of the underlying problem for which the shoulder was injected. The symptoms could also be a reaction to the shot. Joint infections do occur but are rare. The symptoms of infection are joint swelling, warmth, redness, and increased pain. If anything feels worse than before the shot, call the doctor who injected your shoulder.