I squeezed my 6 month old son a little too tight after feeding and sounded like a pop in his stomach pls help?

My son is perfectly fine now he is 2 yrs old runs and plays fine but i was just thinking of this incident and wanted to know if anyone could figure what it could have been. When he was 6 months old I was feeding him a bottle and after feeding he was crying, so i but his pacifier in, and held him in my arms. He kept crying so i held him a little more firmer and then i heard a pop sounded like it came from his stomach, like fluid pushed through a tube. All along i always worried about this, the doctors checked him and said nothing was wrong. Look im not an abusive parent, like i said my son is over 2 years old now and fine, but just was curious if someone ever encountered this. Please help i am a real worry freak. Thank You to all that respond.