I only took 12 hours spring my senior year and pass/failed 4 of them (which means they don't get factored into GPA). Of course, when I bombed (I mean BOMBED) one test, it dropped one of my grades to a C. So when you get a C in one of only two classes in a semester, it results in a pretty sh*tty GPA. So just keep in mind the lack of buffer if you get a less than satisfactory grade.