I'm 32 and I hadn't run since highschool. I started in june and I've been slowly ramping up my milage. Im currently at about 40 mpw. I had ramped up recently, I turned my average 5 mile runs in to 6 mile runs. Yesterday my knee felt a little sore. I thought it was just because it was cold and rainy out. This evening, I took my 7 year old daughter on a 2.5 mile run. I was planning to run after, but towards the end of our run, it was clear something was wrong. I went inside and iced my knee and half an hour later, my knee is fairly swollen and I can barely walk. Obviously, I'm going to take some time off, but how long should I give it?