Hi, I have gone through your query and i can understand your anxiety. Levonelle pills or morning after pills has common side effects like stomach upset, breast tenderness, tiredness, lower abdominal pain, irregular menstrual cycle varies between spotting to heavier flow. Your symptoms might be due to the pills, as the day of intercourse and menstrual cycle are near by there is no possibility of pregnancy. Also you are missing your periods for 3weeks, i advice you to do serum beta HCG to rule out pregnancy. Hope I have answered your query. Let me know if i can assist you further. Regards Dr.Yogapriya.V, General and family physician