You are smart to be cautious. Back in July, there was a larger hack, before they implemented the security layers that they have now. It's been stable for quite a while now. Even so, it's always possible someone got your password. I would recommend changing it. From your wallet screen, you can click on "password" and follow the prompts to generate a new secure password. Keep a good record of it and then submit the change. Then you can cancel your power down if you didn't want one, etc. Good luck.