Thanks for writing in.
There are many reasons for delay or missing periods or secondary amenorrhoea.Pregnancy
is a physiological (normal)
It can also occur in some medical conditions like:
Polycystic Ovarian disease
Excessive physical exercise
Certain medications used to treat mental health conditions
Disorders of the endocrine system, such as hypothyroidism
(an underactive thyroid gland).
Please have yourself examined by a doctor and necessary blood tests and an ultrasound
scan of your pelvis.
Hope this helps.