i suggest you not worry so much. :wink:
seriously, though ... as long as you don't try to claim the design as your own (which we already know you wouldn't do) or try to sell us anything related to the quilt, the magazine, or the pattern, and don't also post (or offer) copies of the pattern, etc. you can post your picture with no worries. it would be courteous to say which magazine, issue and pattern you used. it will also save you time 'cause i'll betcha lots of people will like what they see and will ask if you haven't already said.
:P