Not going to the vet the first time you cat vomits isn't a crime....
It's called being knowledgeable about your pet.
Cats get sick for several reasons. If your cat has been extra vocal lately, it means something is upsetting him/her, cats only meow a lot when something is bothering them.
They can get upset if they are
-bored
-furniture has been rearranged
-change of food
-animals outside (usually other cats)
But one of the most upsetting things for cats are when new people are introduced into the living arrangement, or people are taken away. When a cats owner is suddenly gone 10 hours a day the cat misses them, and often causes them, especially very young and older cats, to get sick.
Sorry if that was a windbag answer, but hope you got what you wanted to know!