Howdy, yes, this is what happens when plants are close to dying, they will have one last attempt at producing seeds as a survival instinct. I would suggest harvesting right away and in future, harvesting when there are 5-10% fresh/white pistils (hairs) left and not to wait until all the pistils have turned brown, as by that time, the plant is well and truly past its peak and has entered a decline in health and vitality. Also any THC is already breaking down into CBN and CBD, producing a heavy, sleepy type of stone, with very little high/up feelings. Just think how much you have learned with this first grow and how much you will be able to use this knowledge with your next grows! After 35+ years researching this wonderful plant, I learn something new every season! Congratulations for your first harvest; I am sure these will be a wonderful experience, being finally able to enjoy "the fruits of your labour"! Not to mention your very own "total quality control"!
Hope this helps... Organoman.