No flowering in Stretch?

I put my 4 fem skunks into flower a little over 2 weeks ago, at around 18-24", they are now around 36". My ? is do the plants flower while stretching or do only do that after they are done. How big are they gonna get before they start to flower? and when they do how long from then to harvest? When do I start giving them Bloom nutes?

They will throw out a few pistils whilst stretching, but all the good stuff happens afterwards. They can stretch up to 2-3 times when flowering (strain dependent) and the flowering time usually is 8+ weeks (again, strain dependent). You should be giving them bloom nutes now, in conjunction with veg nutes.