What Causes Frequent Pain In Forehead?

my son occasionally says his forehead hurts. he hardly ever complains even when he is sick, but he does say his forehead hurts from time to time. Should i take him to his pediatrician for an answer? He generally keeps playing and does not continue to complain about it over and over very often. Yet when he does say something is bothering him 9 times out of 10 he says the forehead hurts.