This does not sound like an allergic reaction, but instead, that the infection is not responding to the antibiotics. You should call your physician immediately, tell them that your symptoms haven't gotten any better and in fact are getting worse, and you need to be seen ASAP. You should be seen and examined, to determine if the infection has (like you suspect) gotten worse. A localized infection like this can progress to much deeper infection (a "cellulitis" or "fasciitis") and, if left untreated or treated improperly, can become very dangerous indeed.
So I would suggest that you make the call immediately and request to be seen immediately.
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