They have up to 2 years to process an Article 15. Odds are the JAG is just running a little slow, and it may take a month or two to process the paperwork. I would be surprised if they hit you with an Article 15 at the field grade level. I could see a summary or company grade. They may wait until you graduate to administer an article 15, but that seems unlikely in my opinion.
The best bet might be just to lay low, be the model professional Soldier, and hope it blows over. You might find the related posts useful: