Hello, First of all, you should undergo one home pregnancy test or blood test for beta-HCG to confirm/ exclude pregnancy at the earliest. In exclusion of pregnancy, reasons for irregular delayed period are ovarian cyst, hormonal imbalance, stress/anxiety, thyroid problem, weight gain (that you have) / extreme loss, irregular eating habits, psychological factor etc. Need to investigate properly to pin point the diagnosis by USG lower abdomen, complete hormone assay, thyroid profile, blood sugar & prolactin level, blood testosterone level etc. Consult with your gynecologist for proper guidance and take suggestive measures. Avoid stress/ tension, take healthy diet with Vitamin & iron supplements, control body wt by regular physical exercise and take sound sleep. You may need to take hormonal therapy to regularize period with other supportive medication. Be well and take care.