6 weeks from the appearance of flowers, or 6 weeks from the switch to 12/12 lighting?
I agree with tony on inspecting the trichs. Lot of good articles here on when to harvest, depending upon the maturity of the trichs AND the type of smoke you are looking to produce. There are some advantages to harvesting 'early'.
I really can't tell anything about the conditions of your plant's trichs from these photos. However, the buds look nice but a little small. Assuming trichs are clear + cloudy, I would keep going, maybe even another 10 days - 2 weeks.