i had to wait around 2 months before i got my call.. then after my call it was another 8 weeks until ground school so a long wait!
i had problems with my application though which is why i had to wait longer than everyone else. i lived and worked overseas for 2 years so they wanted to process that security check also before they approved me.
this is my timeline -
4 Oct - AD
10 Oct - got a call requesting additional info for reference check
11 Oct - Reference checks completed
20 Oct - Medical & Security email
26 Oct - Did Medicals, sent in Money for Security
waited for a long time - emailed them and they kept telling me it was waiting a security clearance. eventually found out that they werent aware that i'd sent them my overseas clearance before in previous emails. Then told me they would follow it up right away (this was around late november)
16 Dec - Golden call!
10 Feb - Ground school!!