question about the final flush

I'm growing some Light of Jah right now and its goin into week 12. The site I bought the seeds off of (and every other site I can find) says this strain takes 10-13 weeks to finish.
At about week 6/7 the stretching stopped and the buds started to fill out nicely. Then they stopped filling out completely for a couple of weeks and nothing really grew. I noticed a little bit of brown was developing on a small part of the roots, so I cut the brown part off. Not even 10% of the root mass. The roots have tripled in volume since, I'm in week 11 and the roots keep getting bigger -which brings up another question, I thought roots don't grow during flowering?
But anyway my real question is now the plants are going through another growth cycle... Like, all the buds were filled out and had stoped growing, and now all the colas have new buds growing from the tips. My main colas have grown an extra 4 inches already.
They look a lot like early flowers. You know, nice green bud leaves, and small little buds developing. Should I start the flush cycle next week? I'm getting close to when I would start flushing, but I'm worried about flushing and these new buds that are developing won't get the right amount nutrients to keep filling out... I've never seen any strain do this where it stops stretching, fills out, takes a breather for a few weeks, then starts stretching again!

I flowered this thing at 8 inches tall, and its well over 3 feet now, of nothing but bud. Definitely a heavy yield for a Sativa, but this is also my first Sativa grow and not sure if this is normal, or what to do with the flushing if it's growing again. I really don't want to have to wait even longer... I mean 13 weeks is a long ass time lol. and now its looking like it might be longer? Is it possible Jah just isn't ready yet?