Make certain the county or record agency does not also have copies of delayed certificates. Sometimes if a certificate was not filed when the event took place, one will be filed later. This is is most commonly done with birth certificates and generally when the person "needed" their birth certificate and realized that they did not have one.
There may be copies of affidavits or statements as a part of the delayed record and these records may be filed separately from the originals. These are usually filed where the birth took place, but there are always exceptions.