Thanks, busytulip. I thought of it, since my caffeine intake is already so much lower than most people's for my own health, but didn't, largely because I don't think it really helps with my headaches anyway. Ibuprofen and Sudafed often help, but I just can't do it until I'm certain it wouldn't hurt. I used up my last cheap test on the 15th for another BFN. I'm trying to just wait and be cautious in case I'm one of the weird ones that it just doesn't show for a while. Seems unlikely but without AF it just feels risky.
What's weird is, usually my unrelenting, multi-day headaches occur with AF. I feel a bit dizzy, gross (though unfortunately my appetite is still strong lol), and of course I'm on high alert of every songle twinge or feeling in my abdomen. At times in the past week I could swear AF's arrival was imminent...but nothing. And I'm more moody too. This is almost like a period without the blood.