Ok, so I think it works like this.
If you haven't completed at the normal time, maybe for a perfectly valid reason like an injury, it's listed as Incomplete at semester end. If you apply right then, nothing goes into GPA.
Eventually it will be resolved, either as a Fail grade or as a letter (so either an F/IF or a B+ or whatever).
So I think you will enter your case as Incomplete but with a B+ or whatever, and it will get calculated in as a B+ or whatever.