Does this happen to you? I feed my baby, lay them on their side for 2-…

Does this happen to you? I feed my baby, lay them on their side for 2-3 minutes and take a stool, but the baby falls asleep and doesn't want to burp. Then I put them on their stomach for 5 minutes and want to change the diaper and there it is, hiccups? why does this happen? Where did I make a mistake? Tell me experienced moms)