See below. Could be a sign a of pleurisy from lupus or other things, see your doctor to best determine what is going on.
Rib cage pain. Could be caused by many things- most commonly muskuloskeletal related -sprain, spasm, trauma etc- including inflammation like costochondritis. If the pain is worse with deep breathing- that tells you that something irritate the pleura- the outside lining of the lung- that can be caused by pleurisy-caused by different things including lupus, also infection like pneumonia, blood clot in lung etc.