Thank you so much for your kind words, which help me relieve a lot of anxiety! Today I also logged into my USCIS account, and I saw all the 3 letters (biometric, online case number, extension receipt) were uploaded there. I want to know, will USCIS in future upload all the important documents there? I move addresses quiet a bit, so I am wondering will our online USCIS account keep updated for our case? Thanks!