Any time from now to a week will be plenty for this plant.
Not all plants get amber trichomes by the way, therefore basing your harvest based entirely/exclusively according to trichome colour has some problems associated with it.
Once your plants have 98-99% brown pistils, it means her life is almost over, therefore harvesting just before she goes into decline, will give you buds with peak cannabinoid levels. Once she is past this point, as indicated by 100% brown pistils, THC breaks down quite rapidly into CBD and CBN, which are 2 non-psychoactive cannabinoids that produce a sleepy effect, but don't actually get you high.
Anyway, you are right on track to harvest as planned.
Hope this helps, Organoman.