I saw the biometrics update online, i found the appointment letter under the document section in my online account, I haven’t received the physical appointment letter yet.
02/14: Application mailed to Chicago lockbox.
02/18: Application delivered.
02/25: Check cashed
03/01: Receipt Notice/Extension Letter Delivered
Biometrics Appointment Was Scheduled for 3/20
There is a backlog for K1 interview dates, I've seen 5 to 8 months wait time. CR1 dates are a bit faster at 2 to 5 months depending on how busy the consulate is with DV visas.