If they are photoperiods, you either stick to 12/12 from here out or push through a re-vege. They are almost certainly in flower based on your description.
It's a matter of 10+ hours of uninterrupted darkness. If they got that even one night, it's now in flower. A re-vege is a very long process. There's no guarantee, but a little hope they are too young to flip to flower. If you go with a continued vege, if you see 'preflowers' at the nodes within 5-10 days, it's going to re-vege for sure. Absence of these would be a great sign it never went into "bloom phase".
So, depending on your "complete darkness" comment... did oyu open the tent up a buch and let light in there for more than a few seconds? that would help avoid flip to flower.
6 day vege is probably going to give you a ~50g plant? Depends a lot on how fast your plants typically grow. So, that is probably important to your final decision.
A re-vege can get messy. if you start seeing excessive branching, don't be afraid to prune some off. Other visible signs are unusual leaves - no seration (smooth), 1-2-3 fingers etc. Just be systematic.. cut every other branch off (leave as many leaves as possible, of course) or something similar to keep it controlled and spaced out enough. "monster cropping? i think it is called is not really a good name. if unmanaged, it won't improve yield, it'll just give you a ton of tiny buds and 5x the work at harvest, lol.