[UPD] Asking My Prof About Final Exam Score

My final exam score in one of my majors has been released, and I got a lower (like as in lower) score than I expected. Shocked is me because I'm quite confident that I can get at least 84%, but instead got a line of 7 percent, which prevented me from getting an uno liner final grade. Should I ask my prof regarding my score? Or are there any instances na ba na prof encoded a wrong score or something? Tack!