Hi, this is as per based on my experience..,u can start with your medical,DS160 and ,payment as long as u have your MNL# .if u started communicating with the embassy through email they will send you through it..but u do not need to wait for the hard copy via post office it will take long..ask a copy of the documents that your fiance(e) recieved,especially the one with the MNL# u can use that document on your medical at SLEC..pls pray before u have your medical it will help. Thanks