Question about follicular dev (female repro)

[CuriousGeorge2]

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I'm a little confused by something I read. I always thought that a follicle goes from a primordial follicle to a Graffian follicle during the follicular phase of the menstrual cycle. I just took a look at my histo text and it says that it takes an average of 90 days (!) for a primordial follicle to fully mature - so it takes 3 menstrual cycles for the follicle you ovulate each month to actually develop?