You should mail all your documents to the one in St. Louis. It took 15 after the mail arrive at St. Louis to appear on DOS website. My friend took 14 days, and another labmate took 18 days. In general, less than 20 days.
If you have further questions you can ask me at lau.changchang@gmail.com
If you have further questions you can ask me at lau.changchang@gmail.com