It qualifies as menstrual migraine when attacks hit on day -2 through day +3 of your period in at least two of three cycles ¹. Timing is the whole diagnosis, so two or three months of tracking confirms it ².

These attacks are genuinely worse than your other ones: within the same woman, perimenstrual attacks last 37 to 50 percent longer, hurt more, and come back within a day of treatment more often ³. They also carry more lost workdays and disability than migraines that don't track your cycle ⁴. Over a year that's roughly twenty to thirty days gone.

The fix is short-term prevention: a five-to-seven-day course started two days before bleeding. A long-half-life triptan roughly doubled the share of periods that ended headache-free ^{5 6}, and high-dose naproxen does similar work for a fraction of the cost ⁷.

Confirm the timing before you medicate anything. The prevention only works if you know when day minus two actually is.

Starting the course on day one of bleeding is the usual reason it "doesn't work" — the trigger fired 48 hours earlier and you're treating downstream.

The first correctly timed course is often the tell. The near-certain wreck becomes a soft headache or nothing. By the third cycle the anticipatory dread of the bad week fades, because your body stops having its prediction confirmed. By a year in you have twenty to thirty days back — not as a figure of speech, but as the plans you used to cancel and the deadlines you used to move around one week a month.