Stunted @ 6wks flowering?

Have 2 femed afghan kush special (Flowering peroid 6-8wks). And i'm at 6 wks. one has rock hard buds, the other is fluffy,loose and pistils all white and not turning amber and compacting. Did a healthy flush 10 days ago. Did the flush stunt? if someone could chime in , it would be great. Thanks.
 
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