When to take Step 2 CK?

I am entering the 2014 IM Match as a US IMG, and thus am trying to get my application done by September 15. I have two options.

1) Write the exam during an elective and have the score report on Wednesday Sept 11.
or
2) Write the exam with a week of pure study time before it, and have the score report on Wednesday, Sept 18.

Please let me know which of these is better. Will having the Step 2CK score three days late be a problem? How bad is it? Thanks in advance.