You need a much closer look at the trichs to determine how long you've got... if you don't have a microscope or a loupe, you could always use your phone and zoom in on the trichs - then zoom in on the picture you've taken and at least you'll have a fighting chance of seeing their color... I'm guessing you're pretty close by the look of the pistils but you can't judge on them... You're going to want to see about 30% amber before you chop - start flushing when you see you're getting close.
Good luck! That one bud looks awesome!