This is not a simple answer and depends on the location where the work was done. If its the front third, then 3 months is a fair estimate. People will notice not that you had a hair transplant, but something is off.
Here is the dilema,you keep your hair long in fear of the scar showing or shock loss.
The redness gets better, but not quite there yet.
The Bozo affect because the transplanted hair is not long enough.