I always thought an ellipsis at the end of a sentence replaced the period, totalling three dots.
Keep in mind the source.
In syntax, an aposiopesis arises when the 'if- clause' or protasis of a condition is stated without an ensuing 'then- clause' or apodosis. Because an aposiopesis implies a trailing off of thought, it is never followed by a period, which would effectively result in four dots.