The time it takes to become pregnant after discontinuing birth control pills varies. According to "Taking Charge of Your Fertility," women may begin trying to conceive immediately after birth control is stopped, but to become pregnant your menstrual cycle must return to normal, as it was before birth control was started. For some women, this will occur within weeks of stopping birth control. For others, it could take several months.
Wait until after you have had your first period after stopping your birth control pills to begin trying to conceive. While it is possible to become pregnant immediately, MayoClinic.com notes that by waiting at least once cycle, it is easier for your health-care provider to determine your due date. The start date of the last menstrual period is used to determine when your baby is due. Without that piece of information, it is more difficult to determine.
Have sex frequently around the middle of your cycle, at the time when you ovulate. Women release one egg per month at ovulation, and to increase the chance of pregnancy occurring, sperm must already be waiting to fertilize the egg. For women with a 28-day cycle, ovulation usually occurs around day 14 and your cycle begins on the first day of your period. If your cycle is longer, your ovulation day might be later than day 14. Having sex too early or too late in the cycle will not result in pregnancy.
Use ovulation predictor tests to help determine when ovulation will occur to better time sexual intercourse. These tests can be purchased in grocery and drug stores, or online. They measure a hormone known as the luteinizing hormone, which increases immediately before ovulation. Some women resume ovulation immediately after birth control pills are stopped, while others can take a few months. Using ovulation predictor tests will help you determine if ovulation has resumed. If it has not, it might simply take more time for your body to return to its normal cycle.
Consult with your doctor if you have not become pregnant in six months to one year. Pregnancy-info.net reports that 90 percent of women become pregnant within one year of stopping birth control pills, and on average it can take your body three months to return to full fertility.