What Do Swollen Lymph Nodes In The Inguinal Area Indicate?

I am a 63 YO male in reasonable shape. I am post bilateral TKR 8 weeks. stitch abbesses developed in the left incision 2 weeks after surgery. I have been on Keflex 500mg QID for 10 days, added Bactrim and 10 more days of Keflex BID. The abscesses got much worse, then got better toward the last few days of the treatment. I have had swollen lymph nodes in the inguinal area for about 3 weeks that has gone from point sensitivity to generalized swelling over a larger area. Over the last 2 weeks it has spread to my neck. No problem breathing or swallowing. I have seen 2 ER docks and my OP surgeon. No infection shows, no fever, and labs are within normal range. all have dismissed the Lymph involvement as a bug that is going around. Since ending the antibiotic regiment, the swelling is slowly getting worse. Is there a test for infection in just the lymph system or some other thing I should do other than just wait for this to run it s course?