The headache that would not go away

It started on a Sunday night, when I developed a headache.  It was a dull headache, and I took a couple of pain relievers when I went to bed.  On Monay, the headache was still there, but I went to work.  At work, I took a couple of tablets of aspirin every four to six hours, but the pain would not go away.  And so it continued into the next day. My mid-morning on Tuesday, the head started to throb and I went home early, stopping by the supermarket to get some of my "cold-killing" remedies.  I started to run a fever, and the headache would not go away.  I strated to think I had the flu, but it didn't make sense.  In previous times I've had the flu, it's hit me like a brick wall. In this case, my headache had gotten worse gradually over a two day period, and it was about to get worse.