Dear nancyjo,
I'm going to assume that they used a standard venous system approach and there were no atrerial punctures. It is possible that the ambulation caused the fresh clot to open and the bleeding could have created a hematoma. Basically this is a big bruise and it can take several weeks for this to resolve. Six weeks seems a bit long. I suppose another possibility is an AV fistula but this does not usually cause pain. An ultrasound would rule this out. I would make an appointment to see your doctor for next week. Explain the nature of the symptoms and that you need to see him when he gets back in town.