You're never gonna see ALL your trichomes turn cloudy or amber, it's producing new heads as it grows fatter. The key is to examine your plant in different areas and take a consensus of your findings. Remember too that things will continue to ripen during your dry and cure phases. Pistils on your lower buds that doesn't fully develop will usually stay white and in some strains even top bud pistils don't brown much. Don't worry about breeder timetables though, they're generally best case scenarios that lean on the early side. Trust your instincts and what you see when looking at the trichomes. If you need to let your plants run longer, there are ways to support heavy branches like stakes or you can even tie them up from above.