Debbie,
I had a swollen lymph node about 1 month after surgery. My doctor told me that this is quite common and not necessarily an indication of cancer. He ordered a needle biopsy to be sure that the node was free of cancer and the swelling diminished about 10 days later. I'm hoping Stephen's case is similar.
In any case, be as assertive with your doctor as you can be, and demand that the relevant tests be done as quickly as possible. Everyone on this board knows the agony of waiting for test results and this should be conveyed to your doctors.
Good luck and hoping for good test results. - Sheldon