Yesterday (May 6) was the regular registration deadline for the June 2014 LSAT, but it's still not too late if you want to take a shot at that test: the late registration deadline is May 16. That's also the deadline for withdrawing from the test with a partial refund, but I don't know why anybody would do that... changing to a future test date would seem to make more sense. Here's a list of the most important dates: Late Registration Deadline: May 16 Test Center Change: May 18 Test Date Change: May 25 Withdrawal Deadline (no refund): June 8 June 2014 LSAT: June 9 Scores Released by Email: July 7
If you're already registered, but you're not sure whether you'll be ready in time, note that you can always WD on the night before the test. You won't get a refund, but it won't count as one of your three attempts.
Don't take my word for it on any of these deadlines... make sure you double-check on the LSAC website. And please call or email any time you have questions.