The fact that you have taken emergency contraceptive
pills thrice in one cycle speaks for itself. These pills contain high dose of hormone and hence disrupt the hormonal
milieu of the body. Even with a single dose, you may have withdrawal bleeding, delayed cycles etc. In the current scenario, you need to see a specialist, get a blood test
along with a trans-vaginal sonogram to assess the status of the pelvic organs. If everything is fine, you could be given hormones to induce a period. Hope this helps.