"Yes. Even though breastfeeding may suppress or delay menstruation, you can still get pregnant. Ovulation will occur before you start having menstrual periods again, so follow your doctor's recommendation on the appropriate birth control method to use."
"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."