Description of your symptoms points towards blunt injury .It is impact of the rod you hit with your head has beeb causing localised pain .Any impact will have some pain or swelling
A significant head injury will cause progressive headache ,nausea/vomtinig or dizziness .
If you have any one of these go to emergency room to get CT scan.
Next Steps
Since you don't have any issues other than the localised pain ,take paracetamol as needed and ice pack application to the injured area