Hello, You took plan B about a week ago, you had been drinking. You should always avoid taking other medication or alcohol when on contraceptive pills as they can reduce the efficacy of the CP taken due to side effects and interactions. Presently, when using the bathroom you had huge blood clots and dark colored blood. The bleeding stopped and your pad is clean. Plan B can lead to unexpected spotting and bleeding. It can cause heavier or lighter bleeding or getting your period earlier or later than normal. It is not a cause of concern. But when the bleeding continues or when you miss your periods, you should get clinically examined by a Gynae, get pregnancy test done. If positive you will be managed accordingly. If you are not pregnant and are not getting periods your gynecologist will recommend few required blood tests, imaging tests and investigations done so that you can be treated accordingly. Stay away from addictions if any. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician