It is very common to experience menstrual changes, including lighter or scanty periods, for a few cycles after taking an emergency contraceptive pill. This happens because the high dose of hormones temporarily alters your natural cycle and usually resolves on its own. First, please take a home pregnancy test to rule out pregnancy, as light spotting can sometimes occur. Self-medicating with hormonal drugs to regulate your cycle is not advised. If your periods do not return to normal after another cycle, please consult a gynaecologist. They can perform an evaluation and prescribe targeted medications, such as low-dose oral contraceptives or progesterone, if medically necessary.