There is no primary domain set for carlajuniper.wordpress.com. This means that although carlajuniper.com will forward to the site, carlajuniper.com will appear in the browser address bar. To learn more about setting a primary domain, please see http://en.support.wordpress.com/domain-mapping/#setting-the-primary-domain
After you make the domain mapping purchase here > Dashboard > Store > My Upgrades and do the set up it can take between 24 - 72 hours for domain name propagation to take place throughout the internet. You can view the DNS changes here > http://www.whatsmydns.net/ What's important during that stage is to be patient. Note that it's quite common for your own ISP to be last one to flush their DNS caches.