Do you tear-off a piece of leaf, and inspect it on a flat surface, or are you trying to inspect while leaf is still attached? Be sure to check the globular head of the trichome for 'milky' appearance. (not it's stalk)

Pistils are not a good way to assess plant maturity. As they age, the older/degraded pistils die-off. (from wind damage, age, handling, irritation from adjacent plant or leaf, pollination...) But since fresh pistils appear daily, they can not be a gauge of plant maturity per-say.

Plant maturity also doesn't go by a strict calendar. The finish time for each strain is dependant on your lighting, techniques you employ, equipment, experience levels of the gardener, (troubleshooting) the chemicals (nutrients) that you use, and lastly, genetics.

A timeline provided by the breeder is great, but I usually add a couple of weeks to allow for a comfortable finish for any new strain I grow whether sats doms or indica doms.