If the pistils are truly brown, it is an early indication of pollination. Scour for bananas (if you see yellow, double check) and herming which will show dick and ball (where the pollen comes from). Also, if it is pollinated, look to the older calyx and see if they look sunken in or smashed. This could be from outside source or hermaphrodite.
If amber, look to the trichomes for harvest signal. Milky white trichomes on mostly all trichomes.