Botox side effect? I've had it twice before

Although the timing of your Botox treatment and the onset of your feeling nauseous makes one question if the Botox caused your symptoms, it is likely unrelated. As you know, nausea and having an upset stomach can be caused by a myriad of things. You could have eaten something that disagreed with you, or you could be coming down with a viral bug. The fact that you have had Botox before without feeling ill, strongly suggests something else has caused your symptoms. Rubbing your forehead did not cause your symptoms. If your symptoms worsen or persist, please seek medical attention. I hope you feel better. 

THe side affects of Botox are not stomach sickness  and nausea. Its likely you are getting ill from another cause and the Botox injections being a recent treatment are just an incidental finding.If this continues see your physician but the Botox as a culprit is likely not.