More recent studies show a lot of the beliefs about this are most likely false.
It all depends on how much you fed over time so far... since people do such drastically different things at times, it can mean drastically different needs at this point.
the plant uses roughly the same amount of p and k during vege and flower. You may need a bit less N in flower, but nothing like a lot of rhetoric recommends.. for example, zero or near zero is just stupid. There is reputable, repeatable quantitative data that shows this is false. It responds well to N in flower. By taper off i mean i go from 120-130ppm to 110 or so. A 10-15% drop? give or take.
I taper off N down to 110ppm after a couple weeks of bloom, but i've had a bit of darkness creep in last couple weeks of flower on 1-2 plants out of 10. I will attempt a slightly different path next time and hopefully avoid the rare plant showing this issue. This is about what you do over 2-3 months and not last night or the last week. It's simple, but not that simple. I probably feed a bit too much N in vege, but it takes a long time to be an issue later on.
read and react.. always do what the plant says... take and course corrections and adjust feeding habits next time to avoid it. If you do that, you'll have a formula that works for 99% of plants with zero issues seed to harvest... a very reasonable goal for anyone. People make WAY too much out of growing healthy plants. The plant does all the work.