Two weeks is plenty of time to hide the hair transplant, IMHO.
I also wanted to hide the transplant so I also took 2 weeks off work. I am now at 1 week post op and I already have very minor signs of the surgery. I am sure in another week no one will be able to tell anything, especially if I shave my new beard lol.
If I were you, I would go into work one-week pre-op with a buzz cut, then after that week is over, you immediately get the surgery and take two weeks off work.
Before you arrive to work again 2 weeks post op, get the same buzz-cut again, that way the newly implanted grafts will be the same length as the rest of the hair and there will be no signs of the surgery. In addition, people wont think anything of your hair because you had the same hair cut the last time they saw you.
This is all assuming you are doing FUE obviously.
How many grafts are you planning on doing?