Panic!

my baby is 10 weeks and when he was about 3-4 weeks he had fallen asleep while breastfeeding and all of a sudden he threw his hands above his head, clenched fists and his eyes were wide open extremely panicked looking. I instinctually picked him up and pat his back. He didn't burp and just calmed down. 

He's since done this between 5-10 times and it usually happens when he falls asleep while eating (breast and bottle). I assumed it was a panic reflex something about feeding and then suddenly being asleep, I don't know.  It reminds me of when someone is choking like on tv, but he's not choking sometimes he will be asleep for a few minutes and he doesn't burp after.

He did it yesterday and again this morning. Shortly after this morning I put him in his new swing we set up last night. We just replaced the one we had been given w something newer. He started to get fussy so as I stood over him to take him out it happened again. He was completely awake the entire time so this threw me off. Since I had to unbuckle him I couldn't pick him up immediately and he started to cry. (Before I never knew what followed the panic.) I held him for a little then gave him a bottle to calm him and it happened again!  I picked him up and he was fine. I let him hang out on my belly and he spit up a bit. (My sister did a quick search; acid reflux, needs to be burped, trachea issue?). 

Waiting to hear back from pediatrician... Anyone else have this happen?

thanks!