I have had headaches from my concussion for about 4weeks now... is that common? hockey injury.

Post Concussion: Headahes after concussion are common and usually settle down on their own. It is recommended to not return to activity/sports till the headaches (or other symptoms like fatigue, dizziness, lack of concentration) subside. If the symptoms persist betond 2 to 3 weeks (as in your case) it is advisable to see a sports medicine specialist or a neurologist specializing in post concussion syndrome.

Unusual: It is unusual to have headaches for that long a period. A bit more information about the injury-loss of consciousness or external bleeding? Also, one would want to know if the headaches are improving or worsening. If they are worsening, then one should seek medical attention. A scan (ct or mri) may need to be done to make certain that there is no structural cause of the persistent headaches.