I'm contemplating running the bridges too (it'll be a last-minute decision)! I just ran the Columbia Classic 15k last Thursday, and the Run Hit Wonder 10k this last Sunday.

If my legs were still sore after a run on Tuesday, I'd probably run some relaxed, easy miles today to help loosen 'em up....but, I run 25+ miles a week.

Since you were only running 3 miles at a time, more than doubling that distance in one run was way too much an increase (try increasing by 20% every two weeks or so). You just gotta lay off using the muscles as much as possible until Sunday...they'll probably feel good enough to use by then.