Can a person get pregnant while taking the pill?

The combined pill contains hormones that prevent ovulation, which is when the ovaries release an egg for fertilization. Another type of pill, known as the minipill, causes a persons cervical mucus to thicken and the uterine lining to thin, which reduces the likelihood of sperm reaching an egg.

The birth control pill is very effective if a person takes it correctly and does not miss any pill days. According to the Centers for Disease Control and Prevention (CDC)Trusted Source, the pill is 99.7 percent effective with perfect use. This means that less than 1 out of 100 women who take the pill would become pregnant in 1 year.

However, with typical use, the effectiveness of the pill is 91 percent. This means that around 9 out of 100 women would become pregnant in a year of taking the pill.