I Haven't Had My Period Dear BeingGirl Experts, My 19-year-old niece has not started her period. She won't go to the doctor to have herself checked. Should she have any concerns about something being wrong with her? Erika --- Hi Erika, Yes, when teen females reach 16 and haven’t started having periods (menstruating), they have primary amenorrhea (lack of menstrual flow). Your niece needs to see a gynecologist or adolescent medicine specialist. A physical exam and medical history is need for the practitioner to diagnosis and understand the cause. Once this is understood a treatment regime can be planned for her. It is very unusual for a girl to reach the age of 19 and to not have started menstruating. Insist she see her healthcare provider about this. You sound like a caring aunt. I am sure your niece will appreciate your concern when she sees this can be treated. Thanks for your concern and we hope this is helpful. Your BeingGirl Experts Wondering I havent had my period? Get answers from the experts at BeingGirl.com.