How satisfactory/unsatisfactory class count to my gpa?

Hi, I know this question sounds silly. When I was a freshman I took a satisfactory/unsatisfactory 2 credit writing class. I got a U on it and retook it and earn a S. How will this affect my GPA. How should I calculate my GPA will a U and S because this didn't count in my school GPA.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums