Swallow test

Has anyone's LO had this before?

We just got home from his 6month check up. Andy is doing great, got shots done, 22lbs6oz, 28 1/2in (I honestly he'd be longer at the rate he was growing). He's been 100% healthy since birth, never even had a cold.

I mentioned to the pediatrician that he chokes often while he's nursing, drinking water and on his own saliva. I expected to hear a "that's normal" "babies do that at this age" or "he's just practicing a new skill" but I got the opposite response. Pediatrician is concerned and is sending us for a swallow test which is basically an xray to see if there's an obstruction when swallowing. I'm actually a little scared.