Migraine
"It never fails that I get a migraine each month about 1-4 days before my period starts. About that same time, I get terrible back pain from the way my body changes. They started hitting monthly when I turned 36. Yay aging! About 8 months I got a sudden migraine that was so bad I had to run out of an executive meeting and barely made it to the girls room, hand cupped over my mouth. It was embarrassing as I had just started this new job. I decided to see my GP. She put me on Treximet. They are $20 a pill but with my insurance I got 30 pills for $60 - yeha! 
I take one whenever I feel a migraine coming on. They work best at night for me. If I take in the day I feel flu-like and sweaty. But they work!"