You've got weeks to go. It's also not just about trichomes. Take into account the color and shape of the pistils. The hairs will be dark and recede back into the calyx as it swells and "pops" off of the plant in a roundish growth. The trichomes on the calyx itself will be cloudy and maybe some amber, no noticeable clear heads. The plant itself will have a "done" look to it - not as green as it was weeks earlier.