Flowering Time?

I have a plant that was derived from some bag seed. I have no idea what the strain is, so that's now giving me some issues.

This is my first grow so I'm not 100% sure what the plant is supposed to look like when it's time to harvest. I am going to go based on this 50/50 rule or move like what is in the sticky found on this site.

The plant seems to be a primarily sativa plant. I say this only due to its thin, tall growth pattern. Fortunately, I topped the plant during veg otherwise I wouldn't have room. I'm extremely happy with the yield to this point. If I had to guesstimate the plant is yielding well over a pound.

The plant is now on it's 83rd day of flowering. The buds are starting to change color slightly, but know where near what it needs to be. I'm only concerned about the potential length of flowering on this plant.

I'm curious what the longest flowering period some of the more experienced growers on the site have seen? Should I be concerned or could and should it take a few more weeks to actually achieve maturity?

Thanks in advance for your help and comments.

If you saw rapid growth in the last 2 weeks and the hairs are orange/amber and shriviled tops, she is peaking.
The longest I had to wait was 9 weeks, not a pure sativa. The shortest was 4 weeks (popcorn buds).