"Pulling out before the man ejaculates, known as the withdrawal method, is not a foolproof method for birth control. Some ejaculate (fluid that contains sperm) may be released before the man actually climaxes. In addition, some men may not have the willpower or be able to withdraw in time."
"While this is possible, it is important for us to acknowledge that everyone has a different and unique experience using contraception. While one may not menstruate at all, another may have heavier or lighter periods while another’s cycle may not be affected in any noticeable way."