To dream that you oversleep some important meeting or to wake up, means that you are actually afraid of oversleeping, because of the importance of situation. The oversleep may also indicate the fact that you are too tired.
Dream dictionary: Oversleep dream meanings
To dream that you hear an alarm clock in your dream could simply be heard the ringing of an actual alarm clock. This is very common dream for everyone. If you dream that your alarm clock went off and you over slept some important meeting, means that you are being afraid to oversleep and miss important things in your life.