"Mommy, my tummy hurts!"

It doesn't take long for a child to learn that the words, "Mommy, my tummy hurts!" will produce instant action on the part of Mommy.  If the kid is lucky, it will mean a day home from school, lounging around watching unlimited movies and being waited on by Mommy.  If Mommy is wise, she'll think twice before assuming the worst.

Junior is thinking, "I don't want to go to school today. We're having a test.  I have to sit by a GIRL.  I'd rather play my video game.  I think my tummy hurts."

Mommy is thinking, "Hmmmm, Junior ate a good breakfast.  He looks and acts normal.  Isn't he having a test today?  I think we'll chance it and see what happens."  And Junior is sent off to school, complaining all the way.

Mom, I think I have the plague!

Most likely, Junior will be fine once he's at school.  It's possible that he DOES have a tummy ache, but probably caused by some level of anxiety, not illness.  Your observation of his behavior is key.  You can usually tell when your child is legitimately sick.  If he seems ok, he probably IS ok.

My mother was a master at seeing through my attempts to stay home because I was "sick".  If I managed to actually stay home, I had to stay in bed, no TV and only books to read.  I couldn't get up to play after the other kids were home from school and only had simple, bland food to eat.  It wasn't very enjoyable and I usually miraculously recovered enough to go to school the next day.

Poor Moms!  We're the ones who need "sick days"!