Go to http://www.fafsa.ed.gov/fafsaws89c.pdf
read Section 1 Student Information, Question 14.
I am not sure if use of AP now will make you eligible noncitizen, but on the other hand, it only mentions J,F, and G visas. so I guess you could try, at least spending a couple hundred of dollars will not hurt you. Maybe return is huge. I would give it a shot. Go to Canada and come back the same day.