Should I flush now or wait another week?

Not yet, congrats on the grow, looks great. Your harvest time frame will come when your plants trichomes start to mature and she thickens up a bit. trichomes that are mostly cloudy and a few amber is the best time. Link below is a good little tool to spot trichomes https://www.amazon.ca/Universal-Phone-Camera-Lens-Smartphones/dp/B07C923LVJ/ google trichome chart to find visuals of what your looking for. This is from my diary of that lens in action. they do an ok job. https://bucket.growdiaries.com/static/post/photo/31185/1657265_fastbuds-blackberry-grow-journal-by-m0usefastbudsblackberry.jpg defiantly have some time left. maybe 4 weeks maybe 3. Best of Luck and Happy Growing!