I ve had a mild dull aching headache for the past 4 days. It s localized to the back of my head and i haven t had anything like vomiting, confusion, dizziness or anything like that, just the pressure in the back of my head. It has been all day, it doesnt really get worse but it comes on about 20 minutes after waking up. I have some slight tension in my neck and shoulders when i try to stretch my neck also. I can t see the doctor until Thursday, but is this something i should be concerned about?