Privacy Settings taking effect

I searched the forum and couldnt find this specific issue, so i apologize if it has been addressed.

I had my site set to block all search engines. Recently, probably approx. 5 days, I changed the setting so that my site would be searchable; however, when I go to google or yahoo and type in my domain, it does not show up.

Can anyone tell me how long it takes for this change to take effect? Or if there is possibly an issue with WP?

Thanks