There shouldn't be ANY bad sectors on a five month old drive. I would contact WD regardless of what data lifeguard says. And I'd back your data up. Any personal files, folders, music, movies, pictures, documents, etc. that you have that can't be replaced, get those saved onto other media now, while you can, just in case. It never hurts to play it safe AND you should ALWAYS have EVERYTHING important saved to more than one distinctly different location at ALL times anyhow, because sometimes, often in fact, hardware simply fails "poof" with no warning of impending failure.
It's not meant to be a scare tactic, it's simply a fact, and common sense. If it's important, put it in more than one place so you don't lose it if you have a catastrophic failure. THEN, after you do that, you can start playing around with testing to see if there is an ACTUAL problem, or a false reading. I can guide you through that as well, but I won't do it until I know you've taken steps to back up important files because every SINGLE time you do anything on that system, it is accessing that hard drive and if there IS a problem, it's making it worse and worse. At some point, that data will be unrecoverable or the drive could simply fail outright.