I'd say it's safe to start your flush cycle . Your plant in showing lots of classic signs that its nearing it's harvest within the next 2 weeks they are really going to start showing ( leaves yellowing for nothing , swelling of the flowers slows , no new pistol hairs coming out ) you're going to finish with some outstanding product ! And if it ends up going for a third week then just feed it some more water no big deal . I hope this information helps you on your quest to harvest day !! Happy Growing !