Scary Moment with my 5 week old

Cooper's been incredibly easy thus far, so I forgive him for scaring me to death this morning at 5am. Cooper was asleep in his swing and I was 2 feet from him on the couch. I had just roused to check on him and then fell back asleep. I hear him scream out once and it wasn't his normal cry at all. Then he does it again. I shoot up from the couch and grab him. He's choking and can't catch his breath. I hear him gasping for breath and start pounding on his back. It takes a good 5 seconds, but he recovers. I have a dr. appointment scheduled for this afternoon. I never want to experience that again! I hope it's nothing serious, and I'm sure it's not, but I don't like that he's been choking from time to time when he's eating and what happened this morning was the kicker.