Nausea, vomiting, headache, stomach cramping/bloating, dizziness, vaginal discomfort/irritation, increased vaginal fluids, or breast tenderness/enlargement may occur. Acne may improve or get worse. Vaginal bleeding between periods (spotting) or missed/irregular periods may occur, especially during the first few months of use. If any of these effects persist or worsen, notify your doctor promptly. If you miss 2 periods in a row (or 1 period if the pill has not been used properly), contact your doctor for a pregnancy test. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor immediately if any of these serious side effects occur: changes in vaginal bleeding (e.g., continuous spotting, sudden heavy bleeding, missed periods), problem wearing contact lenses, dark patches on the skin (melasma), unwanted facial/body hair, swelling of the ankles/feet, weight changes (gain or loss). This medication may rarely cause serious (sometimes fatal) problems from blood clots (e.g., pulmonary embolism, stroke, heart attack). Seek immediate medical attention if you experience: sudden shortness of breath, chest/jaw/left arm pain, confusion, coughing up blood, sudden dizziness/fainting, pain/swelling/warmth in the groin/calf, tingling/weakness/numbness in the arms/legs, headaches that are different from those you may have experienced in the past (e.g., headaches with other symptoms such as vision changes/lack of coordination, existing migraines becoming worse, sudden/very severe headaches), slurred speech, weakness on one side of the body, vision problems/changes. Tell your doctor immediately if any of these rare but very serious side effects occur: lumps in the breast, severe stomach/abdominal/pelvic pain, mental/mood changes (e.g., depression, suicidal thoughts, persistent trouble sleeping), unusual tiredness, dark urine, yellowing eyes/skin. A very serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.