13 week af and still no amber....

Not all plants get amber trichomes, as this is largely a function of genetics and not necessarily the only indication of when to harvest. If you have 95-98% brown pistils, harvest. This example shows why basing harvest timing according to trichome colour only, is flawed. Pistil colour reflects the (true) health of the plant, and it is plant health that determines trichome composition, whereas trichome colour does not. Once a plant has 100% brown pistils, death is close for the plant and a near dead plant can not support healthy cannabinoids, particularly THC, which breaks down into CBD and CBN, two non-psychoactive cannabinoids, that produce the heavy and sleepy body stone type of effect, rather than a THC influenced mind bending head high of earlier harvested flowers. So, depending on which type of effect you prefer - harvest at 90-95% brown pistils for a THC influenced head high or harvest at 98-100% brown pistils for a CBD influenced body stone. THC levels are highest at about 90-95% brown pistils, whereas THC quality declines rapidly once the plant has 98% or more brown pistils. Going by your pictures, I would have harvested 1-2 weeks ago. Leaving this plant much longer will give you an inferior smoke, due to the diminished THC content in the trichomes and the high levels of CBD and CBN, which as I said earlier, are 2 non-psychoactive substances that will relax you, but not get you very high at all. Don't worry, you are not the first person to harvest so late due to waiting for the theoretical/mythical "30% amber" trichomes, whereby you have a plant that does not get amber trichomes. I have grown plants that have had 75% amber trichomes after only 4 weeks of flowering and harvesting after only 4 weeks of flowering would be foolish, and this is another example of why deciding on harvest timing based purely on trichome colour is not ideal. Hope this helps, Organoman.