AOS timeline

I am hoping someone can help me here, we have recently filed my wife's AOS packet and it was "delivered to the pheonix PO Box" on february 17th, I know its been less than a month but we havent gotten any updates at all after that.

A friend recently mailed their AOS packet "delievered march 2nd. they already got charged today march 5th for the processing fee's. on her package tracking it said "Individual picked up at post office"

Is there something we should be worried about? anybody has had this happened where it just says delivered at PO box but not picked up, and still processed fine?

any help is greatly appreciated