Schedule a personal meeting at your closest USCIS (or whatever the immigration office is called these days) and explain it to the officer. They can give you a t

Schedule a personal meeting at your closest USCIS (or whatever the immigration office is called these days) and explain it to the officer. They can give you a temporary "paper pass" you can use to travel until paperwork completes if they find your reason sufficient. Best friend's wedding might not qualify as a good enough reason, but combined with the long delay it might - definitely worth your time talking to them. I know someone who got this kind of pass to visit her sick father.