I think that bloat CAN happen to any size dog, it is just more likely to happen to big dogs, because of their body structure. It often happens to puppies, and sometimes to adult dogs. A friend of mine lost her adult dog to it, very quickly. It IS the stomache area that bloat happens. Look at the page that Sudilar linked too - scroll down and you'll see (not the one with the A - further down - where it happens.

PLEASE! Tell your mom! At least ask to call the vet! I don't want to scare you, but I don't want you to lose Chewy, either! We can't tell anything over the Internet, but a vet can help you over the phone or in person.