its an autoflowering strain?thats my guess. if it continues to flower even after switching to the veg light cycle its autoflowering , 2 weeks of 12/12 from seed should not show sex after that small amount of time, it should still veg till its mature enough to show preflowers. the preflowers are a sign of being mature enough to flower but it should take 3 or 4 weeks at least before they are mature enough if you start from seed on 12/12 to show sex and for it to start pushing out pistils like that. dont kill em dude. if they are not autoflower- lots of newer growers will intentionally sex em and toss em back into veg like that, its not a good thing to do but its not a big deal usually, its just it takes a while to revert em after forcing them to show sex while if you take a cutting and sex it it's faster and easier and doesnt slow growth so people like it better than reverting. but your situation is different and you dont have any other options other than kill em so you should revert em, watch for hermies when you start em flowering again.