This can be a hormonal thing.  If you have a good Doctor speak to them.  If you can find a doctor who specialises in natural womans health even better.  There are things you can do.  If you have a compounding pharmacist in your area, speak to them they will know whether there is a doctor in your area that specialises in this as that doctor will deal with them.

Believe it or not, a lot of headaches are at least in part caused by dehydration..Drinking lots of H2O may help alleviate the headache when it comes!1

Good luck!

I get them all the time also...they are ridiculous...the only thing i do is take whatever works as soon as i start to feel it and  when i get to bed i sleep with a cold face cloth on my forehead..most of the time my headaches last throughout my whole period...nothing really works other then just laying down with a face cloth on my head (along with the pain meds of course)

I get a migraine 3 days before I get mine & as soon as I get it my migraine goes. Sorry, I dont know how to stop them. Just another part of being a women I think-dont ya love it-Not!LOL