Many couples reach an agreement and sign a settlement agreement in less than 6 months. The settlement agreement is then submitted to the Court right away. When this occurs, the Court will approve the agreement before the 6 months has elapsed and will issue a Judgment terminating your marriage on the first date after the 6 month period. You are not required to go back to Court or do anything further, it simply means you are still technically married (and cannot remarry) until that date.
Per Family Code Section 2339(a), the 6 month waiting period starts on the day the Respondent is served or the day the Respondent files a response with the Court (whichever occurs first).