Mostly because it's become predictable.
Get up. Feel okay. Think, "I can go to work today. Good deal."
Drink a little coffee. Drink a little water.
Stumble to bathroom either to a) lose coffee and water immediately, or b) lie on the floor in a cold sweat with the room spinning, then lose coffee and water.
Fall prey to a number of nasty intestinal symptoms.
Return to floor. Sweat some more. Feel the beginning of a pounding headache.
Haul self, on hands and knees if necessary, to phone. Phone in sick.
Answer various questions about degree and type of symptoms. Why on earth do they want to know this? *I* don't want to know this about *myself*.
Stumble back to bathroom. Stick thermometer in mouth, note return of fever. Note intensification of pounding headache. Note rumblings of a sort that bode ill for the health of my GI tract.
Stumble, several minutes and one more cold sweat later, back to bed. Lie there panting.
Wake up several hours later feeling borderline normal. Eat half a boiled potato. Meditate on the gastrocolic reflex almost immediately thereafter.
Back to bed, panting. Wonder what everybody's doing at work. Wonder if I'll live long enough to return. Wonder when this is going to stop.
Remember what happened on Wednesday morning. Haul self to kitchen and drink a little ginger ale. Haul self to bathroom to retrieve thermometer.
After ten minutes in bed, take temperature. Fever is unchanged. Head still hurts.
Fall asleep. Wake up. Post bitchy whiny blog entry on illness.
Lather, rinse, repeat.
**For those of you who are thinking that there might be a Little Jo at the end of this, please don't worry. As far as I know, pregnancy occurs most often in people not contracepting and is generally not accompanied by a fever, gut cramps, and other GI symptoms. But thanks for your concern.