Marathon in 17 days. Haven't run in four weeks due to injury. Just got cleared to start training again. What do I do?

Started experiencing pain in my shins four weeks ago. Doctor advised me to rest. After several weeks, pain was still there, doctor had a "high suspicion" of stress fracture, but the CT scan came back negative. The pain has been subsiding over the last two weeks, I've been prescribed a Medrol dose pack to reduce inflamation and given the clear to ramp up my running.

My goal was to run the Chicago marathon on Oct 12. My training plan called for long runs of 16x3, 18x2 before tapering. I ran the first two 16 milers, and have only run 5 miles in the four weeks since.

I'm 80/20 against starting the race. Even if I'm no longer at risk of a stress fracture, it feels like there's a plethora of other bad things I could do to my body running a marathon after four weeks off. And it's hard to imagine that I'm going to have the confidence needed to push through those last few miles knowing that I missed some of the most important parts of my training.

That said, I did all the training runs for four months. I can get in 2 long runs before the marathon. And I've heard from several experienced runners that, "If you can do 16 miles, you can probably do the 26."

Anyone been through this before? What should I be considering when making my decision?