What are the aftereffects of taking emergency contraception pills?

Nausea, late period: You may expect some nausea and a change in your menstrual cycle. Your period may not come when you expect it. If it is more than 2 wks late, you should do a pregnancy test.

Possible side effect: Potential side effects with emergency contraception can include: tender breasts; changes in menstrual flow (spotting, bleeding, early or late period); loose stools; dizziness; headache; nausea/ vomiting; abdominal discomfort or feeling tired. If you develop chest tightness, difficulty breathing, swelling of lips, mouth, throat – call 911. Notify your doctor if you miss your period. See below.