Unforeseen complications

Tuesday night after my speed session I felt a little pang of soreness along the anterior aspect of my left ankle...the so called good ankle. I didn't think it was any big deal, as it just felt like a little muscle soreness. So I pretty much ignored it. I know...this was very smart of me.
So Wednesday, I got up and went down to the treadmill to put in my four miles. About 3/4 of a mile in, my left ankle started hurting again. Bad sign. I thought that I'd slog through a few more miles and see if it calmed down any, and it did slightly, so again...no big deal.
I went to work Wednesday and as I'm working, I realize that my left ankle really hurts. In fact, it hurts so much that I go home at lunch and get tennis shoes to wear for the rest of the day instead of the little cute slip ons that I normally wear.
Long story short, it's now Thursday and after treating myself last night and again today, and cross training only today...my ankle still is mildly sore. It does seem to be getting better, as it's not clicking or having sharp pain anymore, but it's definitely still there. For the love of all that is holy, it's far too early in my training to be having an injury.
Hopefully, after resting it all day tomorrow, I'll be back to close to 100% for my twelve miler on Saturday.