No not nessesarly, it is very possible as they are producing commercially, but I harvest my plants when they are white, not with a significant amount of amber any way. They are supposed to be at their peak when they are white like I said before. Some people feel that if you let them get amber it will change the effects, but to the contrary others feel the opposite. I think effects are mostly determined by the strain and how well its grown, and that most strains have a wider harvest window then some people give them. I've tried leaving plants an extra 2-3 weeks and seeing what difference there was, and honestly I never noticed one. I smoke alot though, perhaps someone that doesn't might feel it, or it could be visible on a test. Any way if cloudy is an up high, and amber is a couchlock high and it does make a big difference, I still like an up high most of the time so I harvest when they are cloudy/white. This harvest I am going to be toying with leaving different clones of the same strain long then others since its the first time I'm running them. I'm hoping to determine what is best for the strains.
So anyway its all up to you now, harvest white, or wait for ambers, and if you wait how long? Personally if its been a good 7-9 weeks and they are all white I'd pull it. Maybe give it 72 hours of dark time to maximize the THC content and then chop her.