I know what it's like to be comfortable with your choices as a parent but still find yourself wondering when so called experts (be they professionals or other parents) tell you to try CC. I don't think it's that normal for a 6 month old to be "sleeping through" by now. Did the GP define sleeping through at all? Some babies do of course sleep 12 hours straight at that age, but an awful lot don't. You could always write the GP a letter expressing your disappointment and attaching some info (there's some good articles in BB) about CC and it's effects on babies.