Is it warm to the touch? Cause it sound like an abcess. 3cc in the quad should be fine - and redness for 2-3 days is ok. But a week seems a bit too long.
An abcess will be warm to the touch and will require antibiotics and/or a shot. Worse case scenario, the doc will have to cut it open. It is possible for an abcess to go away on it's own but it is also possible for it to poison your blood stream and cause serious health problems. The longer it goes untreated the more likelyhood of having to get it cut by the doc.