Hi, the flushing (watering without nutrients) is a bit of a thing; there are many opinions on it. Some say it's overrated, while others say it has to be done. Personally, I only water without nutrients in the last week.
By the way, in your pictures, you can already see some trichomes that have turned amber. When your plants have mostly milky trichomes, they're ready. But if you want more amber, that means the THC is converting to CBD, so you'll need to wait.
I think you can water your plant with just water every 2 days; do that 3 times and then harvest. I wouldn't wait another 2 weeks.