Let them go, patience is difficult sometimes. I've had ( and have now in my grow room ) some plants that seem to go forever past the published finishing time for your strain. I've got some blue dream that is supposed to be a 10 week strain that is in its 16th week and still not 'done'. Radio shack has a decent portable microscope for around 12.00. Well worth the investment.
I picked and dried some of my blue dream at week 13, as I thought they were finished, and it was a complete waste, as almost all the trichs were still clear with no amber at all. It pays to wait until the plant tells you its done, not some seed factory. I learned my leason on that one. I ended up with a quarter pound of what could have been decent smoke that ended up as canna butter instead.
Enviromental factors such as lighting, temperature, light leakage, and feeding play as an important part in the growth rates as genetics. In my case I had some light leaking into my flower room, which I am sure had much to do with the delay in ripening. I am still fixing that situation.
My advise is to not pick it just because you see a few amber hairs. You will end up kicking yourself in the butt for doing so later down the road.
Good luck on your grow
