When a plant is flowering you can still take clones from the bottom branches up to 21 days into flowering.
A normal indica plant will take anything from 7weeks to 11weeks to finish flowering
A normal sativa plant will take anything from 11weeks to 15weeks to finish flowering.
During the tranistion phase from vegatative to flowering the plants will stretch for approx 2 weeks and can double and sometimes triple in height during this time.
When the plants show you their sex this is when budding starts.
You are looking for white hairs coming from the nodes on the plant. If you have white hairs then you have a female. the female is the one you want to keep for buds. When the white hairs show this is when the buds will begin to form.
the flowering period is when the buds form. They do not form after flowering it is the flowering that makes it bud.
J