Took multivitamin on thursday. is it possible it causes nausea for three days afterwards?

No: Multivitamins can cause nausea, esp. if taken on an empty stomach. The B vitamin components are most likely to cause this. But any nausea from this should last a few hours at most. Most of the ingredients in a multivit. will leave our bodies within 24 hours. I can't conceive of any way it could cause nausea for 3 days. If you have nausea for 3 days after taking this there's a different cause.