Hi,
Your belly button has been formed with a technique that needs time to settle. It has a herniated appearance now but this might be due to the swelling of the belly button stalk as it is protruding through the new opening for the belly button. I am seeing your tummy tuck scar and it is very nicely formed and low. This tells me that whoever did your tummy tuck was picky and picky is good. I would think that time will be on your side to let the appearance of the belly button get better.
However, if it does not get better, then you and your plastic surgeon need to discuss the situation and come to conclusions as to what will be done if it does not get more normal looking. Noone wants a flat abdomen that has as its focus a button--like appearance. This is not attractive at this point.
Having said all of this you must remember that you are in the infancy of your procedure. You are only two weeks and probably still have your drains in place !! Let some time go by. Options are easy to settle your situation in a local anesthesia office revision if needed. Get the opinions of your doctor but if you were my patient, I would encourage you to be patient as so many things change with time.
Good luck with your entire procedure. I am sure you will be very happy after you feel more comfortable with the belly button appearance,
Steven M. Lynch, M.D. (Albany, New York plastic surgeon)