Thank you for posting your query at DoctorSpring.com
I have noted your details and am glad to note that CT was normal, ruling out any skull bone fracture or any major bleeding in the brain.
Post concussion syndrome is a possibility, however, headaches persisting for more than 5 weeks need further evaluation.
MRI brain should be done, if possible, please prepone it. MRI brain should be able to exclude other causes, such as mild bleeding (in brain or in subarachnoid space), any small contusion, etc.
However, there is no need to worry, as it would not be any serious cause (as your CT was normal).
I hope it helps.
Dr. Sudhir Kumar MD (Medicine), DM (Neurology)
Senior Consultant Neurologist