@Gresus,some plants take about 3 weeks to really start getting pistils going.. I wouldn't be too worried about it my guess is they are finished stretching is why the stopped growing and you should start to see alot of pistils soon
@Popcorngc, well because they stop to grow. Buds are just tiny. Any progress. To be honest this is a week 3 from 8 but before I have much bigger flowers like now.