What Causes Swelling In Supraclavicular Area?

I am a 57 yo female retired college professor. Onset of symptoms 2 weeks ago;- apparent URI with coughing, sneezing, sore throat. Then one week ago developed grapefruit sized swelling in left supraclavicular/cervical area which my M.D. said were swollen lymph notes. Next day fever of 103 which has now decreased to 1 degree above and below normal. Other symptoms included headached (7/10) pain in lymph node enlargement (7/10) intermittent weakness; i.e. inability to stand which resolved with rest. Saw my M.D twice this past week; he says he is unable to diagnose and suggests Tyelonol; he did take a Strep culture; came back negative. He also ordered a CBC: did not order a test for Mono.



1. M.D. is currently not responding to my phone calls for up to48 hr. period; should I go to ER for this?



2. Are lymph nodes this size typical in mononucleosis?



3. ARe they any additional tests to specify viral/bacterial infection in neck region?



THANKS