I wouldn’t worry too much if you haven’t eaten for a few days. I know of one instance where someone who was seriously obese went on a diet, and aside from vitamins and water, went over a year without eating. I’ve done over a week myself for the hell of it. Unless you’re absolutely emaciated or have some sort of medical condition that creates a need for it, you can probably handle going for quite a while without food.
All that being said, this isn’t to encourage doing it. Just that you’re probably not creating any kind of dire health situation if you don’t eat for a while.