Well, breeders tend to say that its x amount of weeks from when they show flowers, so i would imagine that is the case for yours. But in either case, this is just a rough guide, there are too many variables to say with precision when the dope is "ripe". The best way to know when your dope is ready is to look, most go by the colour of the trichomes ideally looking for them to have turned about 5-95% amber (depending who you ask) I like to take a simpler approach. Does the dope look done? The buds should be swolen and pretty firm if you squeeze them, the crystals should be standing on end with swolen, bulbous, muchroom-cap looking tops. Dope that is a little over-ripe will have lots of broken looking trics and be pretty amber\orange tinged throughout.
Now many may disagree, but i'm of the school of thought that unless you are going WAY past ripe that later harvests almost inevitably result in better dope. In my experience the "stonier" high from going longer is kind of an old wives tale. Sure if you harvest way early you'll not be a burnt out from your dope, but at the cost of much THC that is still in its precursor form CBD, it takes time for the enzymes to break it down into the good stuff. Only after a looong time when the THC breaks down into CBN will this really change the phychoactive properties.
Now, on to flushing. This is a huge area of contention among growers. I was always taught to flush for 1 or 2 weeks before chopping time so that is the way i do it. However i have heard many reputable growers say that with a good long cure (which in my opinion is as important as any other stage of
marijuana production) it makes no difference to the final taste of the dope. After trying a side by side, i have to say i agree, there is no noticeable difference in between weed thats been flushed and stuff fed up to the day of harvest. In any event, there is no discernable difference so why waste the nutes, especially when you've got all sorts of expensive carb suppliments and bloom boosters. As with most things in this wonderful pasttime, you're going to have to use your best judgement, theres too many conflicting stories to take anything as gospel. Try things out and see what works for you, all i can do is tell you what works for me, others may agree or disagree, but at the end of the day, i have a huge jar full of tasty dope to smoke, so i cant be doing too badly.
Anyhow, sorry for the ramble, good luck with whatever choices you make.