Even though you didn't mention about your past menstrual history.
1st of all your weight is much higher than normal at your height. Please take advice of dietician and physio for control.
Obesity can also lead to hormonal imbalance which in turn leads to menstrual irregularity.
Another advice I can give you that please do sonography of abdomen and pelvis. And consult a gynecologist.
Dr Chetan Maandharkar
Queen women's Hospital Ahmedabad