how do you fail a glucose test?

This might be a really stupid question. How do you fail a glucose test? I've been eating super well, but the last week I've eaten a ton of gummy bears and Oreos. I know, terrible haha. Will a couple times of high sugar content make me fail my glucose test in a couple weeks? Or is it just random? Genetic? Worrying I might have already screwed it all up! FTM here and super confused. 😬😩