Confused in Knoxville

Hello,
   my son has a mild case of factor 9 deficiency. Whats confusing
about his situation his doctor tells me he should only have maybe 1 or
2 episodes a year. He complains with muscle pains maybe twice monthly
but he is able to play and continue on with his normal routines after
he tells me he is having pains. Everytime he goes to the doctor, his
blood levels are always in the mild rage. Just tonite he states to me
that he is having an hemophilia episode but 5 mins after that he's
running, jumping and playing normally with his sisters. Two weeks ago
he told me he was having an episode, I didnt take him to the doctor
immediately just to see if it would get any worse. I carefully watched
him the whole day and he never said anything else about it. He woke up
the next day and played with his best friend Micheal and didnt bring
it up anymore. I would appreciate it if someone would share some light
on this subject. Could all this just actually be growing pains? Can
hemophilia "come and go" or should I rush him to the doctor everytime
he complains with an episode?