It all depends on what you are looking for in your smoke. For example my brother enjoys a good stoney high, so he does not harvest till at least 50% of the trichomes start turning amber. Me I prefer a more heady high, so I shoot for 5% amber before I chop. If you are only seeing an amber here and there then chances are you still have some time left on them.
As far as when is the right time for you to chop her down, well thats like me saying what is the best beer for me. Well that kind of depends, do you like a dark beer or do you like an amber beer. It is personal preference and only you will know what you prefer.
There is a thread on Trichomes and the different stages of them, you may wish to read that. Kind of lays out what you can expect depending on which stage of development your trichomes are in.
Hope you figure out what your looking for.
Stoney or heady.
Sorry for annoying you all again but i getting nervous, please give one more advice
Plant still have none amber trich, almost all pistils brown and looks shriveled, many leaves are yellow and dried, but seems like calyxes still getting bigger
So question - can plant lost *power* potency without getting trichome amber?
looks done to me the plant is swelling up big time are the trichome milky i would put it in total dark for two days that will shock the plant making it pop the trichome, It may help change the trichome some plants stay milky with there trichome i not sure whats ones but i don't think your plant is one of them. Is your plant sativa that take 12 to 14 weeks sometimes