After onset of stomach virus symptoms nausea,stomach cramps,etc abt how long till vomiting occurs?feel sick all day &dont vomit does that mean i wont?

Gastroenteritis.: It's impossible to predict whether you're actually going to vomit if you have gastroenteritis. Some people get nauseous but never throw up. Some people have a lot of vomiting. Most people are not at either extreme. It is also possible that you may have something else going on. Be sure that you remain well hydrated. If your symptoms worsen, contact your doctor. Good luck.