My six year old felt pulsing on the roof of his mouth. he has no other health conditions. it happened out of nowhere should i be worried?

THIS COULD BE FROM HIS BABY FIRST MOLARS ERUPTING ON BOTH SIDES.THIS IS NORMAL SINCE THESE TEETH ERUPT AT SIX YEARS OF AGE. SEE YOUR DENTIST IF CONCERENED.

If you don’t see anything there, and it has stopped, I would not be concerned. Certainly mouth pain can occur from the 6 year molars erupting, although that is not quite what you’re describing. I would recommend seeing his doctor if it recurs.