Why Do I Feel Nauseated, Dizzy And Shaky At The Time Of My Menstruation?

Hi
This doesn't happen all the time. But when it happens, it lasts for a while.
I've been feeling nauseas, it feels like I want to throw up but there's nothing, eating makes it worse, I'm dizzy when this happens and I'm also shakey. Im not pregnant, that I know. I've been feeling like this on and off all the time. I have no abdominal pains and no cramps, that only happens when I menstruate.