Hit my head kinda hard, possible concussion?

Today I hit the upper right part of my head my hitting myself(don't ask why) and I felt something move inside my head. I don't have a headache, dizziness or nausea except Im having short time memory loss and I'm getting kind of confused. I hit myself pretty hard but not intense, it was with the palm of my hand. I have a bit of anxiety and I just want to reassure myself that I do not have a concussion.