wow, if you have migraines often enough and severe enough to be disabling, you should be seeing a headache specialist, or neurologist with alot of experience or specialty in headaches.
Hormonal fluctuations can set off migraines, but why didn't they during monthly fluctuations if you have real migraines? Caffeine will constrict capillaries, and, at the wrong point in the migraine cycle (constiriction then dialation,inflammation, and spasming) will make it worse, although in the later stages helps some people.
How do you know you have migraines? Just because triptans (so-called migraine rescue drugs that constrict cerebral blood vessels) are a really targeted antiinflammatory doesn't diagnose anything, for example -- I have TMD, diagnosed as migraines for years of wasted life (see my post of 8/17/08 "TNJ- botox for TMJ, tmd, or jaw clenching not enough - need to stop the activity).
Keep a headache diary, study up on migraines yourself, and get a doctor who has diagnosed them correcctly before and knows how to try preventatives (rarely but sometimes HRT after all other possibilities ruled out), as well as how to give you the latest, lowest side effect migraine treating drugs.