Forget everything you've read in pot forums as much of it is not correct and goes against the laws of botany.
Growing is not black and white...... you don't give them such and such during some week 2, 3 or so, that is noobie talk parroted by forum members, vendor salesmen, charts and such. Your goal is to produce and maintain the most amount of healthy root mass and green foliage you can until harvest.
One of the biggest pot forum myths is creating a N deficiency at any time. You tell me, why would you want to defoliate your plant just when it needs those simple carbos, proteins, etc. the most? If the plant needs more N during week 7 of flowering to retain leaves, then that's what you do, give it more N.
Think outside of the (popular forum) box, learn what makes a plant tick, and you'll be fine.
UB