Hello. I m Dr. Christensen. I m sorry you re having menstrual problems. Femilon s side effects are similar to those of other birth control pills: bloating, weight gain, nausea, breast tenderness, headaches, and fluid retention are among the most commonly reported side effects. Many women experience spotting or breakthrough bleeding, too, particularly during their first few cycles. Birth control pills also increase your risk for gallstones, blood clots, and strokes. Some studies suggest a slightly higher risk for breast cancer in women who take birth control pills, but a six-month course won t increase your risk for breast cancer to any degree. Birth control pills are generally safe, and they re one of the first choices for dealing with the menstrual irregularities associated with polycystic ovary syndrome (PCOS). Obviously, while you re taking Femilon you won t be able to conceive, but women with PCOS usually have trouble conceiving anyway; this is an issue you may need to address in the future if you decide to have children. (Taking Femilon now will not affect your future fertility, by the way.) I hope that answers your questions, and I hope things go well for you!