Welcome to health care magic.
Try to relax. Cool down.
Your age is 19yrs and you have missed period for 16 days.
Also You have irregular period for past 3 months.
I think you are suffering from "OLIGOMENORRHOEA".
It has several causes.
1) PCOD with Over wt
4) Eating disorder
with under wt
So need to investigate properly.
Do the following test USG, LH/FSH level, Thyroid study, Blood prolactin
and sugar with consultation of gynecologist.
Do regular exercise,take healthy diet.
Avoid stress with yoga & meditation
All the best.
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