Help me please? anyone? ??

Here's my story:

I've been out with runner's knee for about a month now. I've gotten the go-ahead from my physical therapist to start running again (or building up to full runs again). On Friday morning, I did 20 minutes of running, broken up into 10 minute intervals, and then I walked for about 50 minutes. Saturday I went back to just walking and everything was fine. It was absolutely nothing debilitating, just a dull feeling. Saturday night, I went out with some friends and was walking around and dancing in flip flops for about 5 hours. I haven't worn flip flops in over 2 months, since I started having problems with my knees. Sunday, I walked again but about 20 minutes after getting off of the treadmill, I noticed a very dull pain in the top of my right foot. It kind of came and went all day. When I woke up this morning, it wasn't any worse. I did the 20 minutes of running this morning, followed by the walking and it's a little sore in that area now, but nothing bad. Sometimes, I feel it when I walk, but other times I don't at all.

I should also mention that if I rub that spot where it hurts, I can feel a sore area, but there's no HORRIBLE pain if I press on it or anything. Does this sound like a stress fracture? I can't imagine that running for 20 minutes at a relatively low speed would give me that problem, but I'm going to be completely devastated if I'm out AGAIN after runner's knee and everything. A little help here? I can't see a doctor because I'm off at school and the student medical center is closing for holiday break.