There are several reasons of missed/ delayed period besides pregnancy
like hormonal imbalance, stress/anxiety, ovarian cyst/PCOD, thyroid problem, wt gain or over weight (that you have), irregular eating habits, psychological factor etc.
Need to investigate properly to rule out underlying pathology by USG lower abdomen, Thyroid profile, LH/FSH, blood sugar & prolactin
level etc.So consult with your doctor and take suggestive measures.
Avoid stress, take healthy diet with iron supplements
, control body wt by regular physical exercise and proper sleep. Maintain genital hygiene properly and need antibiotic therapy in case of excessive vaginal discharge
Be well and stay healthy.