I Had A Wide Excision For Melanoma On The Calf

I had a wide excision for melanoma on the calf and a sentinel node biopsy 2 months ago. Everything was clear-margins and nodes. Two days ago I was having intense pain in my upper thigh/gun and a very large red area was present. Doctors in Emerg did an ultrasound to rule out a clot and prescribed an IV antibiotic delivered by a pump every 8 hours for 5 days. At a recheck today, the ultrasound showed no change although the red area has somewhat diminished. By the end of the day the pain worsens so that I can hardly stand it. Should I Call for an appt with the surgical oncologist who did the SNB? I don't feel much better after 2 full days of treatment. I'm afraid the doctors in Emgency are not familiar with the complications that can present after SNB. The Internet has my mind spinning.