Hi--same week same day for me (Wk3D3)! Felt a tinge in the knee during the run and throughout the day it turned into a swollen feeling at the back bend of my knee. Hindered bending at the knee. That night my upper inner thigh felt sore. I iced knee and nsaids and didn't run for 10 days. Front of knee sort of hurts and it occasionally feels like it is going to pop. I started program over at Wk1D1 this morning. At 4 minutes into the warmup I stopped to stretch my hamstring and calves. Not much trouble during run except a bit on the ball of my foot. Lots of slow stretching afterward. Doing nsaids today and Blue-Emu cream. I did a leg of a marathon 4-person relay in March and haven't experienced this before. Am hoping it gets better--hiking to Mt. LeConte (over 6k rise in elevation) next month. Really enjoying the program thru week 3. I wished I had done it years ago!