I had a blow to top of my foot almost a week ago- instant bruise. after about three days swelling worsened and strangely around the ankle. i have been off it now for 48 hours but whenever i walk around the swelling worsens again. what's happening?

Fracture: Sounds like it could be a fracture. You should get an xray, to determine which bone(s) are involved. Normally, a bruised area would start healing within 2-3 days. The fact that the swelling has worsened and that the accumulated fluid has infiltrated to your ankle suggests a worse injury. Urgent care not ER would be your best bet, as they typically have the xray machine in house.