the time period the seed bank gives you should mainly serve as a guideline, considering they cant account for every variable in your grow. id keep flushing and check your trichs every day till they are all milky with some amber here and there (depending on your preference of high). but...
have you checked the trichomes under a micro scope? thats really the only surefire to tell. judging from the % of brown hairs id say your good to harvest..however i would double check the trichs