No. It's not okay to lose your leaves this early.
The plant is just now forming new flowers and hasn't really begun on the trichomes.
Natural leaf loss begins around the 6th to 7th week on most 8 to 10 week strains.
If you're losing leaves from the outside in, where the edges dry out and become crispy and the "meat" of the leaves is bleaching out before dying off as well... That's nutrient toxicity. This is VERY common for new growers who begin using their bloom nutrients around this time without respect to ppm levels in the media already.
I'd suggest you post a picture so we can tell you one way or another.