This month, when I had a more normal period again, I ended up with headache today (day 4 of period). Headachy and dizzy and slightly nauseus. Some ibuprofen helped. But what is it that gives me headaches on day 4 of my periods? I'm assuming the rise or fall of some hormone on that day. But which one? As soon as my cramps are gone, and the bleeding is over, I get a migraine-like headache.