well, the timing as also very dependent on two things: WHEN your app is complete and WHERE you're applying.
if you applied early in the season (say now), the turnaround from amcas to secondary to interview invitation is usualy much quicker than applying later in the year when all the applications are in and the med schools have to sort through more applications
plus, how fast you get an interview is very much dependent on the school. some schools like umich are known for being very quick with interviews and have already started, whereas some schools might hold onto your app for several months before deciding to interview.