plants nearly into 3 weeks flower and stop growing tall?

hi, my plants are basically 3 weeks into flowering now , and during the first 2 weeks they had a growth spurt of about 10-12 inches, (now 31-32 inches) but for the last week they have just stayed the same height but are flowering alot , (growing lots of bud) , is this normal?

Yes it's normal after you switch to 12/12 light schedule your plants will stretch for 2-4 weeks depending on strain then they stop and start producing bud