i think i get what you're asking, but it really varies by strain. some strains have more nodes at 4 weeks than others, some strains take forever to show preflowers. but i'll do my best. my last veg round i had 2 kush x haze crosses vegging from seed, a pineapple chunk clone, 2 mk ultra, and a lemon skunk (both strains from seed). both the kush crosses showed sex around week 4 and had 7 nodes each. the lemon skunk grew a lot slower, so at 6 weeks it only had 4 nodes and finally showed hairs. the lemon skunk had been stressed to hell for some reason. the mk ultra both had 5 nodes, but one of them took an extra week to get there. the clone showed preflowers after 2 weeks of veg. as you can see, none of this was probably much help to you but i hope i at least demonstrated how widely this can vary. as long as the plant is healthy, there's no such thing as "taking too long" imo. it's just doing its thing.