My 17 yr old son has been suffering with a severe sore throat for 6 days, He was started on Penicillin on Monday and a throat swab done. there was no improvement and the lump on the left side of his neck continued to get bigger and a large lump also developed on the right side. He has white streaking and swelling in his tonsil area and the epiglottis has shifted. On Wed they changed his antibiotic to Amoxy -Clav combined. He has chills pain difficultly swallowing and increased swelling. I am concerned this is an abscess and I just called to get the result for strep which were negative for Strep. Should we continue to take the antibiotic or should we seek further medical attention?