Hit my head above my temple on a corner of a wall. has been aching and giving me slight headaches for 2 days. should i be concerned? or will it go away on its own?

Not necessarily. Such events can trigger headaches off & on for up to two weeks. If you were not nocked out by the injury I would not worry about it.

Closed head injuries are common, typically benign, and self-limited. Mild headaches are not unexpected. See your doctor if headache worsens, double vision or blurring occurs, dizziness and imbalance develop, nausea and vomiting appear.