Most of the time, using contraception correctly should prevent pregnancy. Birth control pills, for example, are between 95 percent and 99 percent effective. But if you are not careful, it is still possible to get pregnant while using hormonal contraceptives or other forms of birth control.
If You Don't Want to Get Pregnant
Keep in mind that the effectiveness of all birth control methods will vary from person to person and that some types of birth control have higher rates of effectiveness than others. Be sure to talk with your doctor about the contraceptive choice that will best meet your needs, whether that's birth control pills, patches or a barrier method.
Take the pill around the same time every day (if you are using the pill). Forgetting a single day is not likely to result in pregnancy, but if you make a habit of forgetting your pills, you are more likely to get pregnant on birth control. Use backup contraception if you have forgotten to take your pill to prevent pregnancy.
Be sure to follow the schedule recommended by the manufacturer if you are using a patch, Depo Provera injections, or any other form of hormonal contraception. Not changing your patches or other devices or not getting your injections on schedule could mean you don't get the correct dose of hormones and this may increase the risk of pregnancy.
Avoid medications that interfere with the effectiveness of hormonal birth control. Certain herbs, such as St. John's Wort, or pharmaceutical drugs in various categories can render hormonal birth control less effective. Your doctor or pharmacist should be able to give you more information about this. If you have been prescribed a medication that decreases the effectiveness of hormonal birth control, use a backup method of contraception or ask to be switched to another drug.
Don't smoke. Smoking can interfere with the effectiveness of hormonal birth control.
If you are using a barrier method, use it every time you have intercourse. Having unprotected sex, even just once, could result in a pregnancy.
If You Do Want to Get Pregnant
Stop taking your birth control pills or birth control patches, if you are using them. If you are taking the birth control for a medical reason other than contraception, talk to your doctor about alternative ways to address the medical issue. Your fertility should return to normal within a few months after discontinuing the birth control pills.
Stop getting the injections if you have been using Depo Provera and wait for your first normal menstrual period as a sign that your fertility has returned. This may take three months or longer.
Schedule an appointment with your physician to remove your IUD, Norplant or other form of implanted birth control, if that's what you're using. After using implanted hormonal birth control, it may take a few weeks or months before your fertility returns.
Be intimate with your partner just prior to and during ovulation once you have discontinued your birth control and your cycle has resumed. Women who have a 28-day cycle usually ovulate on day 14. You can use an ovulation predictor kit to determine when you are ovulating if you are unsure.
Have patience. You might get pregnant right away after stopping your birth control, or it might take a while. If you have not become pregnant within a year, talk to your physician about testing for infertility. In general, using birth control should not impair your long-term fertility.
Some people might get pregnant after missing a single birth control pill, whereas others might be able to miss several pills in a month and still not get pregnant. When in doubt, use backup contraception if you do not want to get pregnant.
Failure to use birth control properly can result in pregnancy.