I would recommend you still change your email passwords on a known clean computer. See the link in my previous posting for the link to ask Leo.
Even if you don't think you're infected, you may be infected and the hacker may be accumulating info, downloading emails and/or reading emails coming in. When you think they have access to all of your emails and the contents in those emails, you realize how vulnerable you are! They can identify new emails coming in and accounts linked to that email account including accounts you're changing passwords on. They could even change a password on one of your accounts, delete the email, and empty it from the trash.