Pain?

As I started week 4 of the program I started to feel some tightness in my left knee.  I pushed through and each time I ran I felt it, but as I warmed up the pain went away. 

Yesterday, I had taken 2 days off between runs and when I started my run my knee was instantly sore and tight.  Then as the run progressed it got worse.  I tapered off the speed and did finish the last day of week 4. 

As I got home I started to have more pain in my knee.  I am scared now.  I want to keep going, but I've never had a knee problem.  I iced it and currently have heat on it. 

I am scheduled to start week 5 on Monday, but not sure how that will fair. 

I am loving the couch to 5k and the other parts of my body are ready to move onto week 5.  Des gave me some pointers for how I need to fix the way my feet are hitting the ground. 

I'm hoping a warm bath, heat, and then extra stretches will fix me right up!