when you flip to flower there is a phase your plant goes through that looks like nothing is happening, it is all normal and you will see stretching depending on the strain, i have flowered some that hardly did a stretch then others that just shot way up. i prefer the stretchy cause that means ill get more flower sites and to me its all about the buds you get. its like a week or 2 that looks like nothing but the plant is adjusting, usually. by the 3rd week into the 12/12 cycle you see and notice whats taking shape hope it helps and keep growing the magic