My migraine always attack either before or after my menstrual. Each attacks will cause me vomiting?

Common. When you get a migraine the nerves to your stomach essentially cause your stomach to go to sleep. It stops working normally. That is what causes the nausea and vomiting. When the migraine is over the nerves turn back on, the blood supply to the body parts are normal and the nausea and vomiting goes away. I know this is a simplifies answer but otherwise it is too complicated.