Yes. Ellipses usually have three full stops to show that the statement is left unfinished.
Only if the ellipses are preempted by another sentence. Anymore than three full-stops/periods is considered grammatically incorrect.
Three full stops, or 'periods' as some in the US call them, is called an ellipsis. In more formal writing it can indicate that the material you are quoting goes on, but the material is not relevant to your topic. In more casual writing, it can indicate that the writer isn't clear how to proceed, or it can indicate sarcasm, cynicism, doubt, or just a pause in the thought. You have to get a lot from context.
... yeah. An ellipses is three dots...
ellipses
You can insert an ellipsis by typing three consecutive periods (...) with spaces before and after each period, like this: "I am waiting for you ... in the park." Ellipses are commonly used to indicate a pause, omission, or trailing off in a sentence.
== == Three dots are ellipses, meaning that something is left out. If you combine ellipses with a period, then that would leave four dots... meaning that something is left out, and then it ends.
Ellipses are a scientific word for the shape of an oval. for example the planets orbits are ellipses.
The duration of Never Mind the Full Stops is 1800.0 seconds.
Ellipses are not circles.
Two-dimensional, think of circles, ellipses... Three-dimensional: spheres, etc.
An ellipses - or three periods in a row - thusly . . .
Never Mind the Full Stops ended on 2007-04-24.