Sinus pain and pressure for 5 days no congestion. fatigue. no nausea or vomiting. diagnosed with a concussion from unrelated incident. normal neurological test. no ct scan. any chance this could be a brain tumor?

Those simple sinus symptoms do not raise red flag to me.

Agree with Dr Le, and perplexed why your specific "sinus pain and pressure" issues prompt concerns of a brain tumor. Certainly if additional symptoms are present, and a diagnosis is elusive, might consider more extensive evaluation via a virtual consult at HT. (www.connect@healthtap.com).