Pills contain hormones that work in different ways. Combination pills prevent release of egg. Both types thicken cervical mucus to keep sperm from joining egg. Both types also may prevent fertilized egg from implanting in uterus. Advantages Nothing to put in place before intercourse.
Periods become more regular.
Fewer tubal pregnancies. Possible Problems Must be taken daily. Side effects include temporary irregular bleeding, loss of monthly period, weight gain or loss, depression, nausea, breast tenderness, and other discomforts. Often less at clinics. Some family planning clinics charge according to income.