I Had A Concussion 12 Days Ago. Hit The Back

I had a concussion 12 days ago. Hit the back of my head hard falling while ice skating. I have had a headache all day every day ever since, more like a burning sensation at the back of my skull. I have vertigo when I move my head and nausea. I had a ct scan and xray. Nothing abnormal. I definitely feel not right. How long should I wait before seeking more medical advice.