Actually, just my back has been bothering me since the beginning of last week. It felt like I had twisted the wrong way and maybe strained it a bit, and it wasn't getting any better. I mean, during the day it would go away but the next day it would be back. I finally figured it out this morning.
My big bookshelf is next to my bed in my bedroom, and my alarm clock is on top of it. I had been reaching up and over to hit the snooze button or reset my alarm clock for the past two weeks -- I've just been exhausted every morning and finding it hard to get out of bed -- and apparently was twisting my back in a weird way to reach up that high. I wasn't noticing because I was mostly asleep. So when I would wake up, my back would hurt and I couldn't think of how I'd hurt it. This morning I was awake enough when I hit the alarm to notice. Solution: Either get out of bed when the alarm goes off, or move the clock to one of the lower shelves. Duh, Jennifer.