@Pippinwhite -- Thanks for sharing your experience. If my doc ever mentions tri-phasal pills, I'll say no thank you.
I'm on the pill primarily to treat my PMS symptoms. I get teary and weepy if I'm not taking the pills. I also have terrible headaches, bloating and cramps.
It seemed like my migraines were less frequent when I got my hormones leveled out, too. So in my case, my hormones are all over the place when I have PMS. That's what causes it to start with. Birth control pills saved my sanity.