You can wear your hair in any style after your surgery. If you wish to wear bangs after surgery, then go ahead. If you believe there is an issue, discuss your concern with your doctor.
It can take 6 to 12 months after surgery to see results. If you are concerned it is best to contact your doctor. You already had the surgery and at this point you have to just wait it out. Don't waste time reading other's complaints about your doctor.