Harvesting by trichomes is a pretty advanced technique, which leads new growers to harvest early more often than not.
Suggest you research other factors which determine ripeness (pistils all red and curled in, calyxes/bracts swollen and looking like they are seeded (which they hopefully are not)), and only check the trichomes as a reference once those other factors are met. It's gonna take a lot longer than you think, but you patience will be rewarded.