Also, even if you get an interview this late in the game, it's very likely that you're interviewing for a waitlist spot. Not being on the admissions committee, i'm obviously speculating, but most schools have their classes by may (in fact there's a requirement to have all initial acceptances sent by may 15).
For comparison, I was a little later than Don, having my primary and secondary submitted in January, interview in February, and accepted first week of March. To still be submitting secondary's in the last week of April, I'd personally say it's too late. The school will never tell you that, however. Something about application fees. My advice would be to save your time and money, and submit a new primary as soon as AACOMAS opens for the next cycle, that way you'll have a seconday in by september and interview in october and be one of the first accepted. Good Luck on whatever you decide.
-E-
COMP 2008