Your blog is at http://samanthadonbavand.wordpress.com/
If you would like to use your domain name purchased elsewhere and map from your free hosted wordpress.com blog to it, then you will first need to set up domain mapping. http://en.support.wordpress.com/domains/map-existing-domain/
After you make the domain mapping purchase here > Dashboard > Store > My Upgrades and do the primary blog 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.