Hey everyone, I'm new to the forum and I've only been running for just about a year. I've been training pretty intensely over the last 4 months for a half marathon next sunday

I started getting this pain last saturday around mile 7 of a 12 mile, moderately paced run. Out of nowhere I got this shooting, almost stabbing pain in what originally felt like the underside of my knee. I stopped to stretch but no luck with that. After a while it seemed as though the pain moved towards my upper calf muscle, just below the underside of my (right) knee. I powered on the rest of the way even though I don't know if that was the right thing to do.

I rested from saturday until wednesday and didn't get a mile and a half before the pain came back. So, I waited some more and went out to do 8 miles this morning since this is my taper week. Again, made it about 1.5 miles and on came the pain. After I stopped running, the top of my calf muscle felt very tight even though it feels almost like a tendon sort of pain.

As a walk it hurts when I extend my foot/toes upward during my step/flexion of the calf. If anyone has any information on what this might be and how I can remedy it (hopefully in a week) I would really appreciate it. I read a few threads on here and heard a few different options, one was the popliteal tendon, any insight? I've trained too long and too hard to miss this half next week.
Thanks in advance for all your help.

Vinnie