No certification shall be made or summons or certificate issued under this section until after five o'clock in the afternoon of the fifteenth day following a state election, or, in case a state-wide or district-wide recount is held in accordance with section one hundred and thirty-five, until the tabulation and determination under the preceding section have been revised in accordance with the results of such recount; provided, however, that such certification may be made or summons or certificate issued on or after the seventh day following a special state election, unless a candidate who received votes at that election files with the state secretary, not later than five o'clock in the afternoon of the sixth day following the election, a written statement of intention to seek a recount or otherwise to contest the election.
Unless I'm reading this incorrectly, since this is a special state election, the certification can't issue until 7 days after the election, and if any candidate files a request for a recount on or before the end of the 6th day, the certification doesn't issue until the recount issue is resolved.
Whether there is a recount may depend on the vote differential:
After a state general election, the Secretary of the Commonwealth must hold the recount petitions until after the official tabulation of votes is made by the Governor and Council. If the difference in the number of votes cast is more than one-half of one percent of the total votes cast, the district-wide recount will not be held. If the difference is one-half of one percent or less of the total vote cast, the Secretary of the Commonwealth must order the registrars of each city and town to proceed with the recount.
Per the MA Secretary of State, there must be three days notice of the recount date, and it could be scheduled up to 10 days after the recount filing deadline. So if a candidate filed on the 6th day, and 3 days notice is required, there would be at least a ten day delay of certification.
Under 2 USCS § 1a and 1b, the Governor must certify the results to the President, countersigned by the Secretary of State. So neither the Governor nor Secretary of State can act alone in certifying the results.
Here's a Daily Kos diary on the recount procedures and laws. And Brian Ross at ABC News adds his findings, but curiously, only discusses Coakely moving for a recount, not Brown.