My laptop made a strange sound?

A few mornings ago, my laptop made a loud sound like a clicking noise. It sounded like it was coming from where the fan is located and lasted only a few seconds. I know sounds like this are usually indicative of impending hard drive failure, but it hasn't happened since and the computer is operating completely normal. I've updated my backups just to be on the safe side, but what could this mean? Should I be looking into purchasing a new laptop or am I worrying over nothing? Laptop is an HP and a little over 2 years old, btw.