Help!

Yedterday night i was on youtube, i was very tired, and in a failure i clicket on one of the Google-add's in the corner ... named " Gulf Hurricane Relief " or something ...
I entered a website where you could donate to help with the rebuilding of some hurricane accidents or something ...
Stupid as i was i entered the site again to take a better look ...
Well, it was no phising-site, cause i checked it...
Okay my point is that im pretty scared atm, they cannot charge me without my credit-card code if im right?
I really dont hope so ...
But at least i had my spam-filter up, and i scanned my computer after.
I entered a website where you could donate to help with the rebuilding of some hurricane accidents or something ...
Stupid as i was i entered the site again to take a better look ...
Well, it was no phising-site, cause i checked it...
Okay my point is that im pretty scared atm, they cannot charge me without my credit-card code if im right?
I really dont hope so ...
But at least i had my spam-filter up, and i scanned my computer after.