Squash,

I experience the same thing...if I do something that makes my head tweak I just know it will set things off in a few hours.

For me I believe it to be anxiety related and I have started to look at the evidence. Did anything bad happen from the headache, did I become incapacitated? I now do my best to ignore the anticipation of the unknown.....that is not easy at all but I am starting to see some results.

I recently figured I had an anxiety problem when I saw a truck go over a speed bump rougher than I would have and it gave me a headache.... I was standing in a parking lot watching!

Bud