The U.S. Department of Health and Human Services estimate almost 62 percent of women between 15 to 44 years of age use contraception. A variety of birth control pills are available on prescription in the United States with varying amounts of hormones. http://i2.cdn.turner.com/cnn/2016/images/10/04/contraceptive.use.stats.pdf
There are different types of pills Most women will usually begin to ovulate normally and have menstrual periods a month or two after they stop using the pill or most forms of birth control. https://www.qfg.com.au/trying-to-conceive/female-fertility/after-contraception
In general, you may be able to get pregnant within 1-3 months of stopping a combination pill (this is the most common form of oral contraceptives). But some women can get pregnant within a year. One study even found that women who took the pill for more than 4 or 5 years were more fertile than those who used it for 2 years or less.https://www.webmd.com/baby/get-pregnant-after-birth-control
According another study made by United Kingdom’s National Health Servicehttps://www.nhs.uk/conditions/contraception/when-periods-after-stopping-pill/, it can take a while for your periods to come back after you stop taking the pill. Most women will have a period around 2 to 4 weeks after stopping the pill, but this depends on you and what your cycle is normally like. Weight, health, stress, exercise and conditions such as polycystic ovary syndrome (PCOS) can all influence your cycle. Your periods may be irregular when you first come off the pill, and you should allow up to 3 months for your natural menstrual cycle to fully re-establish itself.