There are several reasons of long time delayed period (3 months) like ovarian cyst/ PCOD (most common), hormonal
imbalance, stress/anxiety, thyroid
problem, wt gain/extreme loss, irregular eating habits etc.
Need to investigate properly to rule out underlying pathology by USG lower abdomen,Thyroid profile, other hormone assay, blood sugar & prolactin
level etc. So consult with your gynaecologist at the earliest and take suggestive measures. Proper treatment can only be made by pin point diagnosis.
Avoid stress/ anxiety, take healthy diet with iron supplements
, control body wt by regular exercise and take a sound sleep.