Your original work is under copyright protection as soon as it's created. The process you refer to is the registration of the copyright. I agree with eparys, that registering the copyright is only useful if you are willing to go to court after finding an infringement. (Even without registering the copyright, you could still go to court to stop someone copying your work, if you have the documentation to support that it is your original work.)
The only original part of a quilt pattern is usually the pattern itself - words and pictures - since most of the designs are not sufficiently original to be placed under copyright.