All of my friends that have left for BOLC as AD officers all got their ID cards at least a few days before leaving for BOLC or the day before they left, some a month before. They are AD as soon as their orders start, which is not the same day as their first day of BOLC. I guess it depends on the card office you go to and if they can pull you into DEERS, but with orders in hand and a start date, you should be good.
I'll second that statement.
My son's report date back in 2012 was June 1st, per his orders he was activated on May 25th, long travel time from Seattle to Ft. Rucker. His promotion to 1LT came exactly 18 months from May 25th.
He was told to just get his new CAC during inprocessing.