Gagging can be something deadly. If your babies gag too much they can choke themselves. It is not something to play around with. Now some babies will gag on their bottles, because they are in their mouth too far. But if you find that your baby gags on a pacifier or when you lay them on their back in their beds, you will want to talk to your pediatrician about this.
Parents should try to be smart about calling their doctor all the time. Sometimes it is hard to know when to call and when not to call, but hopefully with experience you can work this out. Do not be afraid to ask your doctor question about when they think you should call or when it is something you may be able to take care of yourself.