having Mixed signals about harvest

So I have 5 different strains that have been flowering under a 1000W hortilux for 8 weeks and two days and they look beautiful. They are covered in milky and clear trichomes but it is hard to tell if any are amber and none really stand out. This is my first grow and I have never looked at weed much under a microscope. Also I used a product called overdrive by Advanced Nutrients that is supposed to extend flowering time by a few days for increased yeild. The only one with noticeably swollen seed catalyx isnt supposed to be ready till the ninth week anyway... I am getting mixed signals and just want to chop at peak time. Any advice? Also any one have any pictures of amber trichomes with out any color added to it?
THX

haveu s3en this