Donna, please excuse my laughter, but we are not the quilt police! Your post actually sounds like you are afraid you will be arrested! LOL Relax, quilting is not meant to be a science. If you need rules of quilting let me give you my two best ones. Rule #1 enjoy yourself. Rule #2 finished is better than perfect everytime.
An eighth of an inch is going to matter during the constuction of a block. But consistency is going to matter more. If your finished block is smaller, just make sure all your blocks square to same size and you should not have a problem. Yes the finished size of your quilt will be smaller, of course. Remember that every 8 seams will subtract an inch. You may want to reread the tips posted in this topic. These are the voices of experience and there is no reason to attempt to reinvent the wheel. :lol: