Levonorgestrel drops are a type of emergency contraceptive used by women. After use, this drug may occasionally cause some mild symptoms of adverse reactions, including nausea, vomiting, breast tenderness, headache, dizziness, and fatigue. Usually these adverse reactions do not need to be treated and will disappear on their own after 24 hours. If these symptoms are more severe, you can see your doctor to see if they need to be treated. In addition, the drug may cause abnormal bleeding from the uterus, mostly in the form of early or late menstruation in the month of taking the drug, and in some cases, irregular bleeding, which usually disappears on its own. If it is severe, you can see your doctor to see if you can continue to take this medication.