Stomach flu or...?

Had my glucose test yesterday and felt totally fine after, except maybe a little lethargic and had a slight headache. Then before bed I started to feel a little yucky. Woke up in the middle of the night and have been up since with diarrhea and vomiting... Could this be from the drink or perhaps coincidentally a stomach bug? The nausea and stomach upset has not gone away and I have been trying to down water as best I can. Has anyone had this happen so many hours after the glucose test?