Daughter 14, to be 15 in Feb 2018 has had her period for over 16-18 months. She has not had it for 2 months, maybe 2.5 months, and is under severe stress, but in a loving home now since Aug 2017. She is not complaining about pains symptoms of any kind, and proclaiming she has not had sex. Can stress just be the cause of this? shouldn t we take her for an exam in the event she does have an unusual mentstral cycle, or let it play out? She is overweight and has not been physically active since Sept 2017. Thanks