What Causes Migraines,lethargy And Mood Swings?

I have been expereiencing miagraines, lethargy, irritability, mood swings, all at the time I have my period. The headaches seem to be lasting two or three days. What can I ask my GP to test just to make sure things are ok. I know this is common with periods, but I am certain that the level I am having shouldn't be ok.......