Hi there.. Delayed periods could be because of many causes like Significant weight gain or loss,Overexercise,Poor nutrition, anemia, hypothyroidism, Smoking,Eating disorders like anorexia nervosa,Increased stress, Polycystic ovarian syndrome..when periods are delayed usually the flow wil be longer.. I suggest you get your hemoglobin and tsh test and usg done once. Have more iron rich foods like green leafy vegetables, pistachios, dates as your losing more blood and could become anemic...for now to reduce flow take tablet tranexamic acid(500mg).. Consult gynecologist once for complete examination..