I may be wrong here, but I THINK in cases where a 'Civil Ceremony' is performed, the information is directly at hand, and consequently, the ensuing certificate is possibly available far more quickly than is the case with Church Ceremonies - or so I'm given to understand, anyway - as I believe there's a tendency for the latter bodies to "drag their feet" in lodging marriage notifications with the NSO ... by submitting those on a bulk basis ... say once a month or so.
Perhaps you could clarify if Myrna and I will be given an 'initial interview' when we go to the Embassy to deposit my CNI ... ?