Yes sir, discontinue any nutrients 14 days prior to harvest always, just pure water.
The last 14 days should be clean water feed every time for best smoke and end product quality. You don't want left over nitrogen in your plants its what makes them burn hot and taste almost spicy on the tongue. Definitely begin "flushing" (feeding just normal water) if you're only 2 weeks out from harvest.
I would not look for heavy run off either if your doing a 14 day flush, just water the plant until a tiny bit of water drips out of the bottom of the pot. As they say "shoot for 10% runoff". So with 1 liters of water you should only see 0.1 liters of run off roughly.. It takes time to eyeball it but you could always drain into a clean tray and measure with those easier to lift plants.