1. Missed periods and use of oral contraceptives before or during early pregnancy.

Occasionally women who are taking the pill miss periods. It has been reported to occur as frequently as several times each year in some women, depending on various factors such as age and prior history (your doctor is the best source of information about this). The pill should not be used when you are pregnant or suspect you may be pregnant. Very rarely, women who are using the pill as directed become pregnant. The likelihood of becoming pregnant is higher if you occasionally miss one or two pills. Therefore, if you miss a period you should consult your physician before continuing to take the pill. If you miss a period, especially if you have not taken the pill regularly, you should use an alternative method of contraception until pregnancy has been ruled out; if you have missed more than one pill at any time, you should immediately start using an additional method of contraception and complete your pill cycle.

There is no conclusive evidence that oral contraceptive use is associated with an increase in birth defects when taken inadvertently during early pregnancy. Previously, a few studies had reported that oral contraceptives might be associated with birth defects, but these findings have not been seen in more recent studies. Nevertheless, oral contraceptives or any other drugs should not be used during pregnancy unless clearly necessary and prescribed by your doctor. You should check with your doctor about risks to your unborn child of any medication taken during pregnancy.