Why have I been nausea and vomiting for the past 3 days nausea vomitting kind of achy and weak

?virus. You probably have a virus, but be aware that you can get dehydrated if it persists. The norovirus last longer than the common "stomach virus." increase clear liquids, than slowly increase your diet to soft foods (brat diet). If you do not recover, than you need to see a dr. And get evaluated. Good luck.