First time Swimming with 6 month old!!!

Today, I took my 6 month old to a baby and me swim class. There were much smaller babies there swimming and even being dunked under. 😳 Anyway, we were floating him around and he swallowed a little bit of pool water. He gagged a little bit, and coughed like 3 coughs, and then was fine. It’s been an hour now, and he’s acting normal. Is this something I should call the on call about? I’m a FTM so I’m a nervous wreck about secondary drowning or something....any advice, or input?