I hit my ankle against a metal pole and there is no bruising but there is swelling and pain when I walk, press on it, and move it around. Help?

Likely contusion. You could have a chip or a stress fracture, but more likely a contusion. Most likely you have a bone bruise or contusion. This is when your bone swells from the inside due to trauma. Stay rested, ice, off-load and take antiinflammatory meds. If pain continues over 1 week, see a doctor. Hope that helps.