First let me say you really won't need to worry about flushing. Its broscience, and doesn't do what you think it does, but I don't really want to get deep into that right now.
You need to count that 10-ISH weeks(breeder times are just a guesstimate, not a rule) from when the plant started to form flowers. If a breeder quotes a seed to harvest time its usually BS because there are to many variables to make those claims.
If you count the 10 weeks from when the flowers started, you should have a much more realistic harvest guesstimate.
The hairs(stigma) on the buds will start to turn redish, and will shrink. That is one of the first signs the plant is beginning to mature. Once 90% of those stigma have done that, THEN the plant is in its final 1-3 weeks. During that final time the buds won't look like they are growing any bigger, but they are swelling internally, and packing on weight and density. During that last 2ish weeks the buds are ripening as well. That is the point you can check trichome maturity if you want.
It is very easy to harvest a plant early and miss out on its full potential, it is VERY VERY hard to over ripen a plant. I've never seen someone accidentally let a plant grow to long.