Since you did mention that you have been having these symptoms for the last 4 days after the head injury
, you should not ignore this,specially if you feel other symptoms such as vomiting/nausea
associated with this sharp pain
. You should consult with your physician so that firstly plain xray of skull can be done to rule out any underlying fracture
and if deemed necessary by your physician after neurological examination, a CT scan
of the head can also be ordered to rule out any damage to the underlying brain and surrounding tissue layers. Hope this will help. Regards.