I am taking metronidazole for a possible vaginal infection and drank 3 glasses of wine last night. what will happen to me?

May cause vomiting: You'll probably be ok since it was last night and you don't seem to have any side effects from it. However, avoid drinking while taking the Metronidazole as it can interact with the alcohol and you may have severe nausea and vomiting. Also, drinking may make the antibiotic less effective. https://www.drugs.com/food-interactions/metronidazole,flagyl.html

No worries!: It is commonly believed, and advised by many doctors, that metronidazole and alcohol cause nausea and vomiting. It's an urban myth that was disproved many years ago. In my STD clinic, we do not advise patients prescribed metronidazole to avoid alcohol. Anyway, if somehow the side effect were true, you would have felt it right away with your first glass of wine. Don't over drink, also don't worry!

Metronidazole: Alcohol with metronidazole can make certain people develop nausea , vomiting and feel unwell . If you are feeling fine then probably nothing should happen but avoid alcohol if possible.