Stopped nutes too early?

i've had plants where pistils were 80-90% white at end... that's why they aren't a good indicator to go by. you need to look at trichomes. google for all the varied suggestions on that, but at the least, it is more correlated to thc potency than anything else that's simple to use at home. pistils can turn brown when they get pollinated. 2 more weeks seems close to reasonable -- give or take, tough to tell in pictures and having never grown that specific plant. you are in soil, so i bet you can push 2 weeks. You can always give it some more, then stop again. flush is 100% not neccesssary except in cases our own behaviour makes it neccessary. do what makes you feel right, though.