No period in two months. haven't been sexually active. vagina dryness. no mater how aroused no lubricant is realeased. 19 years old. what's happening?

Uncertain: Reasons for missed / late period include: an anovulatory cycle in which no egg is released, marked v or ^ in weight; eating disorder; Over-exercising (endurance athletics), stress, travel, significant illnesses, oral contraceptives & other meds, Illegal drug use, breast feeding, hormone imbalances and medical problems (i.e., PCOS). Pregnancy is #1 reason. If this goes another cycle - get eval.