Ummm... You wouldn't be having nausea the day after opiates typically. It could have to do with your body readjusting after using it, especially if your body isn't used to foreign opiates (your body has it's own endorphines, so using opiates will throw that system out of whack temorarily) If thats the case you'll be fine, if that isn't the case your just nauseous, and you'll probably be fine