No, and this is a common mistake. Overtime for non-exempt employees applies to any single week, even if payroll runs for more than one week.
If you are paid every two weeks, it is not enough for overtime purposes that the total hours for a two week period are not more than 80. If you worked 50 hours the first week and 30 hours the second, and you are not exempt from overtime, you still should be paid the premium rate for the additional 10 hours in the first week.
For overtime purposes, a week is any single period of seven consecutive days. This usually runs from Sunday through Saturday for most employers. It does not have to start on a Sunday, but it has to start on the same day every week.
Learn more here about calculating overtime pay under Massachusetts and federal law.