This is for the September K-1 filers. Welcome! Please keep each other company while going through this process. To properly fill out your timeline USCIS goes by "Received date" and not the notice date.
Example
I-129 F Sent - September 1, 2021
I-129 F Received - September 6, 2021
I-129 F - Notice Date - September 10, 2021
In this example your NOA-1 should be September 6, 2021. This will help you properly fill out your timeline.
For those who have just filed your I-129f application with USCIS, this thread has been created for your needs and for you to be with others experiencing different aspects of this journey. This is a place to ask questions and to share experiences. All are here to learn together. Good luck because this is a lengthy process currently running 5-6 months from filing date for your NOA2 approval.
https://www.uscis.gov/sites/default/files/K1_Process_V11.pdf
Also, since your application will go through several background checks this is a primer on what goes on with the background process.
I know it really sucks, but the best way to get through this is to lower your expectations and try not to compare your timeline to anyone else's. Don't forget that the people here on Visa Journey represent a tiny percentage of all the petitions the CSC (California Service Center) must work through! When someone gets to your file, you'll hear from them. Stay busy, talk a lot with your fianc about non-visa stuff, don't forget to hang out with your friends, take up a new hobby, go to a sporting event, and your time will come! Good luck
The explanation why is it taking so long.
https://www.visajourney.com/forums/topic/681798-august-2018-i-129f-filers/?do=findComment&comment=9558550