1 Girls start having periods at different times depending on how quickly they are developing.  If a girl has not had her first period by the time she is 16, this is still probably normal, but it would be worth checking with a doctor.
IETMS stands for Interactive Electronic Technical Manual System. Israeli English Teachers' Network. Institution of Engineering and Technology Northern Ireland. Institute of Engineering Technology of Ontario (Canada) Interagency Environmental Technology Office (Washington, DC) Industrial Effluent Treatment Plant.
All Acronyms. IETMs. http://www.allacronyms.com/IETMS. Published January 10, 2018. Accessed January 10, 2018. CSE All Acronyms. IETMs [Internet]; Jan 10, 2018 [cited 2018 Jan 10]. Available from: http://www.allacronyms.com/IETMS. MHRA 'IETMs', All Acronyms, 10 January 2018, <http://www.allacronyms.com/IETMS> [accessed 10 January 2018] Bluebook All Acronyms, IETMs (Jan. 10, 2018, 6:01 AM), available at http://www.allacronyms.com/IETMS. CSE All Acronyms. IETMs [Internet]; January 10, 2018 [cited 2018 JAN 10]. Available from: http://www.allacronyms.com/IETMS.