I hit my forehead really hard 5 days ago and my head has been hurting but now it's spread to my whole head. could it be a concussion?

Yes, one can have : a concussion without loss of consciousness. Since your symptoms are worsening, see your doctor tomorrow for a neurological exam to determine if you need an MRI or other studies. Avoid physically or mentally demanding activities like housework, exercise, schoolwork, video games, text messaging & using the computer. You may need to change your school or work schedule while you recover.