August MCATer 2 years ago. Received secondaries in October and some as late as November. But some may differ. Your app won't be considered at all though until your August scores are in. Start filling out online secondaries now and get your LORs ready. Many schools send out automatic secondaries w/no screen that you can send in before you are even contacted to do so.
I've recieved one 2ndary so far, and I have not taken the MCAT yet either. Some schools don't sceen applicants on the basis of GPA and MCAT, so they send out 2ndaries as soon as they get the names of applicants.