Hi- I Recently Had An Excision Of Left Ankle Lipoma

Hi- I recently had an excision of left ankle lipoma which was benign. My ortho surgeon explained post op that the tumor had quite a bit of vascular involvement and was surrounding nerves. My symptoms were burning and tingling. Four weeks post op I still have swelling and drainage and the skin surrounding the incision is dark. I'm non weight bearing using a knee scooter and elevating leg above the heart. Is this common or could there be an infection? The staples were removed after 18 days and I'm now wearing strips on the top and bottom of incision site. I change the dressing every other day.