Hello, that's a beginner mistake to pay attention to the pistils, it's an indicator, but my hairs often turned brown before the plant was finished, that has to do with genetics, temperature, light intensity, etc.
To determine exactly when they are ready, you need to look at the trichomes with at least a 30x magnifying glass.
70% cloudy / 30% amber is the rule of thumb...
But just judging by the pictures, the buds still need at least 3 more weeks, I would take another look at everything then, it would be way too early to harvest now, THC is just starting to form...