Cheating on an exam is read as fear of being unprepared, and as doubt about whether you have earned your place. Dream books link it to impostor feelings rather than to any real wrongdoing.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.