Periods... girls only please (:?

okay so I don't know why but every time I get my period I get sick. like not like just a little. like I will start barfing and I get craps so bad that it feels like someones stabbing me. and when I stand up I feel like I'm gonna faint. And some times I do. I don't know if its like normal to get that sick? I mean just about all of my sisters have the same thing but they said that when you get older you stop getting as sick. but i don't know.