Do not say that you are done, thinking that you can go back at a later stage, because chances are, that you will not be able with other work coming in.
There is ALWAYS, ALWAYS unexpected things that will happen when working on code.
By adding time ahead of time, you will be able to cater for these unexpected changes.
By raising unexpected changes and keep adding work to the tracker/board for these unexpected changes/documentation, you will start getting micro managed.