Yeah, not so long, but still needs to fatten up more. Length of hairs and coloration... (technicially the hairs don't get shorter, the calyxes plump around them.)
A bit too early to pull the scope out, but doesn't hurt to gain familiarity, either.
I try to use multiple observations, because trichome coloration doesn't always play out the same way for every seed. To avoid over-ripening waiting for some level of amber trichomes that just doesn't happen in a normal timeframe, i also consider bud density and pistil coloration. Once it looks the part and no longer fattening up, i put a time limit on how long i wait from that point. This avoids the less common plant that just refuses to amber up.
trichomes looking plastic (instead of glassy) and smokey are good to go. Amber is a sign of degredation, anyway. The idea of waiting for 'some' amber is considering the entire plant -- lower buds are slightly behind.... or further behind than normal if colas are blasted with too much light.