Here's a heads-up for you, because we want you to be safe out there. Mashable has compiled a listing of the sites they know the Heartbleed exploit affected, so you can go change your passwords right now.
They also have some advice:
Some Internet companies that were vulnerable to the bug have already updated their servers with a security patch to fix the issue. This means you'll need to go in and change your passwords immediately for these sites. Even that is no guarantee that your information wasn't already compromised, but there's also no indication that hackers knew about the exploit before this week. The companies that are advising customers to change their passwords are doing so as a precautionary measure.
Although changing your password regularly is always good practice, if a site or service hasn't yet patched the problem, your information will still be vulnerable.
Also, if you reused the same password on multiple sites, and one of those sites was vulnerable, you'll need to change the password everywhere. It's not a good idea to use the same password across multiple sites, anyway.
Major sites were affected, including Google, Yahoo, Tumblr, Pinterest, Instagram, Twitter and Facebook. Click through the link to see the entire list.
I'd also recommend getting a password manager if you aren't already using one. Use them to generate and store secure, hard-to-hack passwords for the sites you visit. They're worth every penny.