Enough sleep??

Last night I went to bed after looking at the clock and thinking that if I slept till around 7, I'd have about 9 hours of sleep. But usually I get 7 hours and that's what I got today. Now, it's just a little after 5 and I can't get back to sleep. What's more, I'm not sure if I want to try to go back to sleep or if I want to go running.

I'm not sure if I should even try for 10 hours of sleep. It might be possible next week though.