Hello… Clinical studies have shown that some women taking Emrgency Contraceptive Pills have intermenstrual bleeding due to withdrawal of the hormone progestogen that is present in the pills. This occurs more frequently when the pills are taken in the pre-ovulatory phase. In your case, you took the pills soon after your periods, that is in the pre-ovulatory phase. This could most probably be the reason for your bleeding. Do not panic about the bleeding. If a urine pregnancy test was done after the missed period and found to be negative, there is no chance of pregnancy. The test usually becomes positive 6-12 days after ovulation, in case of pregnancy. If you are sure that you interpreted the test correctly, then do not worry. You gave a history of delayed periods in the past. It is quite common to have missed periods once in a while. It could be due to hormonal imbalance caused due to lifestyle factors like stress, physical inactivity, sudden loss or gain in weight. I would advice you to not delay further and go to a gynecologist and get some of these tests done (HORMONES- T3, T4, TSH, PROLACTIN), also an ultrasound of the abdomen and pelvis to detect polycystic ovaries. Do not worry about it as all of these can be corrected with timely intervention. I hope this information helped you.