Yer thats about right but some say as long as 10 weeks to get the most out of the plant. It all depends on when your trichs look cloudy. Always judge when the plant is ready to harvest besed on what your trichs look like.
Mine finished at 6 weeks under a 1000W light. I used a small, 7-quart, pot and vegged for 4 weeks. I grow 'em fast with the small pots and daily nute-watering.
Might take an extra week or so if you don't use my speedy system.