Ankle Soreness, Tendinitis?

I noticed during Tuesday's run with my brother (and through today) that I could feel some soreness every once in awhile on both sides of my right foot (underneath my ankle), primarily on uphills and downhills. Therefore, I'll probably wait until this weekend to get in some more miles. It's not a major issue right now but I figure the smart thing to do is to rest, rather than aggravate it and turn it into a bigger problem. I assume that the soreness I am experiencing is probably due to a combination of an increase in miles last week, worn out shoes, and a lot of towpath/road running that I'm not used to towards the end of last week's 34 miler.