Dear Msorano,
I have patterns and books that are copyrighted. Some were printed in Doll Reader and Doll World Magazine, and the publishers acquired the copyrights in my name. Books were through Dover Publications, and again the publisher copyrighted the books in my name. I also sold patterns through the mail, and copyrighted the patterns myself.
If you have given away this pattern without having any type of copyright on it, you cannot copyright it now, unless you change it in some way--add a picture, change wording, etc. You must then write Copyright (c) and the year, with your name. Then register the work through the U. S. Copyright office. Nowadays, you might be able to do that, or at least get the paperwork online. By writing Copyright on the work, you have declared that it is your own original design, and you can then safely distribute it before you get confirmation from the copyright office.
Teri