baby gagging on spit??

so my baby is 4 weeks old and just randomly started choking and gagging, i grabbed the suction bulb thing and sucked his mouth but all that was in there was spit?!

he sounded raspy until i got all the spit out and he screamed til i was done but now he’s fine and sleeping on my chest. i’m a first time mom and EVERYTHING scares me 😩😩 anyone else had this problem with their babies?? and what was the issue?