Hello, Implanting is a good and reliable method for birth control. It directly releases the Progesterone hormone into the circulation thus bypassing digestive and liver systems which a drug has to pass through when taken orally. So it is effectiveness will not be affected by weed or alcohol directly. I hope that reassures you. The discharge from breast might be a coincidental think. it does require a more thorough assessment and investigation. it may be non-significant but sometimes raised levels of Prolactin hormone can lead to this. So, my advice would be that please do not ignore this symptom. See a doctor, who can take a detailed history, examine the breasts and arrange for investigations such as Serum Prolactin levels or imaging to get to what is causing this discharge. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Sabina Hussain