WHATS WRONG WITH MY BABY??

For the last couple of hours my 2 week old son has been sleeping and i can hear his stomach gurgling and making noises and he keeps burping like in his sleep. They're wet burps that sound like there should be spit up with them, and then he sounds like he swallows a bunch and nothing comes out. He's even let a few of those burps out while sitting up and still nothing comes out. Then a few minutes ago he let out this almost scream like sound and then a gag-like cough and i picked him up and he did that two more times and then he swallowed a bunch and now he's fine and asleep in my arms. I'm a first time mom but i've dealt with my fair share of newborns over the years and i'm freaking out i don't know what's wrong with my baby. It's 1:30 in the morning and i don't know what to do and he seems to only be okay in my arms with his head propped up a bit. Any ideas what this could be???