Other risks
Some women worry that the pill may increase their risk for breast cancer, but the evidence remains unclear, notes the American Cancer Society. Studies have found a slightly higher risk of breast cancer in women who take birth control pills. However, women who stopped using the pill 10 or more years ago do not show an increased risk. Discuss the risks and benefits of birth control pills with your health care professional.

There is some evidence that long-term use of the pill may increase the risk of cancer of the cervix (the narrow, lower portion of the uterus). There is also some evidence that the pill may increase the risk of certain benign (noncancerous) liver tumors. However, the actual risk and role of birth control pills in both these cancers is unclear.

Possible side effects
Nausea, breast tenderness and bleeding are the most common side effects of all birth control pills. Most side effects decrease or disappear after three months of continuous use. Switching to another formulation can also relieve side effects.

Saint Johnswort This herbal product that may help relieve mild depression can interfere with the effectiveness of certain drugs, including oral contraceptives. According to Swedish scientists, several women who took Saint Johnswort while on the pill have gotten pregnant.
Antibiotics To resolve a longstanding controversy, the American Medical Association recently reviewed studies and found that yes, antibiotics do occasionally lessen the effectiveness of oral contraceptives. The AMA recommends that if you have experienced breakthrough bleeding or unplanned pregnancy in the past while using both birth-control pills and antibiotics, you should err on the side of safety and use another method of contraception while taking antibiotics.