I have no regrets for keeping my surgery to myself. It truly is nobody's business. You still have to do serious hard work. There are people that have surgery and fail - regain all the weight they lost. They don't follow any diet plan. So just because a person has surgery does not mean they have done something wrong- it does not mean they should have something to hide. Your body is your business. Don't worry about co-workers. They won't be in your life forever. Right?
And you do look fabulous. ENJOY it.