Since Many Days M Suffering From Menstruation Problem. Sometimes It

Since many days m suffering from menstruation problem. Sometimes it tends to come twice a month but the amount of bleeding is very less and sometimes for these three monthss m not getting periods. My weight is.perfectly alright as per my height however my stomach is totally bulgy n fat as i consume junk food a lot. I want my menstrual cycle to be normalized completely. What should i do??? Kindly help.