You still got a good few weeks there mate. The "Right" time to harvest is when the THC is at its optimum levels. This is when about 75% of the pistilles (The white hairs) have gone brown/redish brown.

Saying that, the best way to know is when the trichs turn cloudy.

Its your choise when you harvest, but when you think they look good and ready, give it 1 week, you wont loose, but may even gain. Cannabis plants flower the most in the last 3 weeks of the maturation period.

Its looking good. Have fun with that!