15 business days is the standard, however you could have purchased the Priority procssing service for $150 that would have gotten it to you in 48 hours.
Not much you can do at this point other than wait, or send a politely worded email to the Complaints email address for Los Angeles advising them of your planned travel and ask if it would be possible to inquire as to the status of your application.
You also should have received an email from LA when they received your application stating what their processing time frames were.