Patients usually see an increase in buttock size immediately that goes down over several weeks due to a decrease in swelling as well as disappearance of some of the fat. 11 days out is still fairly early, and some of the contour augmentation is blunted by the continued swelling in the places where fat was taken. I would take nothing at face value until at least 4 weeks out from surgery, but you will continue to notice a change in shape up to 3-6 months after your procedure. I would bring up your concerns with your surgeon if you are worried about your final results.