Pain on Either Side of Achilles

Hi, I am training for the Marine Corps Marathon on Oct 29th and did my long run last Sunday. It was 18 miles and I felt pretty good throughout the run. I woke up Monday morning with pain in the back of my ankle on either side of my Achilles.

I did not run all week but am still having a little bit of pain. This coming week I am supposed to run my 20 mile long run. I don’t know if I should push through or stop running to risk further injury. I am 4 weeks out and am getting worried about not running.

Thanks!