@ZorinZ: You have to decide how ready you think you are. You said "almost certain I will fail it". Does this mean you're nervous, or you really haven't prepared much? If it's the former, I say go for it and then see what happens. If it's the latter, don't you may want to reschedule since it's $100 to do that, and upwards of $300 to reapply and retake a section.
BEC has a lot less material than other sections, so two days is a lot of time to review the entire course (assuming you already understand most topics decently). If you're relearning too much, then move it back. If you're not in a time crunch, I personally would recommend two exams per testing window. One at the beginning of the window and one in the middle of the second month. And again one at the beginning of the next window and the second month of the next window. That gives you about 6 weeks for each section (adjust one week fwd/back for FAR®/BEC&AUD). Good luck!
BEC 86 (08/30/11)
FAR 84 (10/13/11)
REG 88 (11/08/11)
AUD 86 (11/29/11)
Exam prep - Becker self-study