When taking levonorgestrel, you need to fast for two hours before and after, so it is okay if you take it after a meal, but wait until two hours after the meal. This is because then the absorption rate of the drug in the digestive tract can be increased and the effect of the drug can be maximized. Levonorgestrel is a progestin drug that is often used clinically to regulate the menstrual cycle and for contraception. It can be taken once in a while if used as a contraceptive, but is not recommended as a long-term contraceptive. The side effects of levonorgestrel include breast pain, nausea, vomiting, and irregular vaginal bleeding. However, side effects such as these are generally mild and can disappear after a few days after stopping the drug. If you have vomiting within two hours of taking this medication, it is best to take an additional pill.