Is it possible to undo putting my personal information into a site that has security certificate problems?

I went into 1800volunteers.org through the HandsOn volunteering website that i got to from an email newsletter from Starbucks. (Starbucks newsletter -> HandsOn -> 1800volunteers.org). When I went to register for 1800volunteers.org, my computer told me that the website had a security certificate problem. I was sure it was okay, so I clicked "ignore" and went on to register, which involved putting in my name, address, and email. Later, i got a validation email from the site, which told me i had successfully registered, and below the contact information it gave a link to 1-800-volunteers.org, which had no security certificate problems. Now I'm worried that my name, address, and email will be sold to some spammers, or that I'll be hacked by some kind of nerdy terrorists, and that is the last thing I want. What should I do?