i did a google search and found this web site it explains copy right and when it is protected.
copyright.gov
i am shure it will have all your answers it also has the fourms you will need to do a registered copy right
the other thing you will need to do or have someone help you search all patterns like your to make shure that there is not one like your already copyrote there was another pattern i was going to copy right i got a letter back that said my pattern was already done.
good luck it is well worth getting your copyright
god bless you and yours