Mystery Pain: Top of Tibia, Right Side of Knee After Running

Hey Everyone -

I recently started training for a half marathon several months back. I had no history of running and started out running a mile per day with no trouble for a month. I moved up to 2 - 3 miles in month two - also no problems. One day I chose to run 5 miles and noticed discomfort on the right side of knee. It was most painful walking down stairs the following day. After a day or so the pain was no longer apparent while walking. Since then I would begin to get the same pains after the first mile. The pain became progressively worse the longer I ran, until it was impossible for me to actually continue. 

I recall it being less consistant, whereas now I'll notice the pain within the first mile every time. This is even after several weeks of no running. I've spent countless hours researching the problem and have had any success finding problems that match the exact symptoms. 

The symptoms:

• Pain on the right side of my knee; feels to be on the lower right side of my knee, around the top of my Tibia/Fibia
• Pain only occurs after running
• When really bad it hurts when walking down stairs
• The pain itself is not on the surface. I tried running just to pinpoint the pain and would apply pressure right on where it felt most apparent (on the round bone that sticks on the right of my right leg just under the knee) but it was difficult to replicate the pain with pressure. That point was the most noticeable, although very minor. It's almost as if its somewhere under that bone.
• If I don't overdo it, the pain is generally gone after running; 
• I've only felt the pain come on very lightly from walking, but only if I've walked several miles straight
• The pain is no where in the front of my knee. On my right leg it is to the right, bottom portion where knee and tibia/fibia connect

I'm 27 years old, no prior leg or knee injuries. I have started to focus my strength training on my hamstring and quads. I've been stretching those muscles more frequently and also just purchased a foam roller to start using. I just purchased new shoes which I was fitted for today. I have an appointement scheduled with a sports doctor in several weeks but would love to get feedback.