I have been exercising more and eating in a calorie deficit, for the past 2 months and those 2 months i had menstruated twice a month. i am also on yaz plus. can the exercise and deficit be a reason for this?

YES: Yes, exercise and weight loss can be one of the causes of hormonal fluctuations that result in irregular menstrual bleeding. As you approach your desired weight and your caloric deficit levels off, you should see a resumption of normal menstrual periods. If you continue to bleed multiple times a month for longer than 4 months, see your gyn dr for evaluation.