question on size of buds

hi i have been seeing some pics of nice big size buds and its only week 4 and 5 and 6 my buds dont look that big and im in 9th week haha
and yes i feed it i use fox farm and i use sunshine mix

any idea why mine seem smaller its my 5th grow and i know im doing it right and i use 400 watt hps but they seem smaller than some of u guys plants at week 4

if your plant is sativa then it will take longer to grow the fatter buds,
you also may not have enoug light

ohh sexy lady with advice haha umm well i use 400 watt hps and i think my plant is a hybrid sativa and indaca mixed cause the top leaves are narrow and the lower leaves are much wider so should i grow 12 weeks in flower or 16 weeks?