67 days and no AF

Cycle day 67 today and still no AF. I've taken 4 pregnancy tests between days 35-64 and they all come back negative. I was on the depo shot for about a year and had my last shot in March, got my first period in June, 30 days later I had my next period, then 44 days, and now I haven't had one for 67 days. I know the Depo shot messes with your cycles for like 2 years afterwards. Should I be worried? Anyone else have anything similar? Should I wait the full 3 months before I go to my obgyn, or should I call now? Thank you!