Projectile vomitting - 7 week old

Ka

My LO is 7 weeks old and this morning we were laying in bed and all the sudden he had projectile vomit go straight into the air from his mouth and his nose. It literally soaked his onesie, soaked me and my bed. He screamed and cried and it obviously hurt him. Then he kept sneezing and more vomit came out of his nose:(

Hes been checked for pyloric stenosis and the ultrasound came back fine. Has anyone elses little one had this kind of projectile vomit? It scared the crap out of me. I burp him after every feeding and hold him upright for a good 15 mins afterwards. He does spit up a lot but this was the first time its been forceful. I'm starting him on Zantac today.