LOL, I just did same thing. Making Wreath quilt for DIL and finished sewing top together, hung up to get a couple of pictures and to take closeups of the blocks to plan quilting. When I transferred pics to my computer I noticed the ribbon bow block didn't look right. I decided to take that section apart and redo as it simply required turning a couple of pieces around. Picked apart grabbed the quilt and went to sewing machine, fixed the block and then ready to sew cream/white piece back in. I couldn't find it, it was missing, tore threw house looking for it and it is nowhere. Fortunately I had extra pieces and was able to fill the missing piece, still have no idea where the original piece is, the move from living room to sewing room is down hallway of maybe 20 yards and don't even ask how many times I and DH have looked in garbage. I am accusing the cats of stealing it to make me go crazy. Pic 1 is quilt top, pic 2 is wrong block, pic 3 is corrected block.