As the factors that go into making a decision on your file depend on the presence of all 3 people at the meeting (so I've heard) - your interviewer, the person who picked your file to be interviewed, and the person who's writing your report - it may take anywhere from 4 to 12 weeks before you actually hear back from them. For me, it was 12 weeks before I got a response.
I'd suggest you wait 2 more weeks. If you still haven't heard back after 12 weeks, then give them a call.
I have a theory that since the class was reported full a week ago, it might be that instead of putting more people on the alternate list and later going through all the trouble with waitlist movement, they're waiting for a) accepted students to withdraw their spots and/or b) May 15 date.
Either case, good luck.
