Do I need medical attention?!

I dropped a steak knife on my foot 3 weeks ago and sliced an artery. I had stitches in the foot that were removed 2 weeks ago. The swelling had gone down; however, the pain and the swelling have increased tonight, but there is no streaking. Is this cause for concern? Could I have started bleeding inside my foot? I have elevated my foot and applied an ice pack. Do I need to go to the emergency room? What are signs of danger? Thank you,