I got pregnant on this method. It is not a safe way to prevent pregnancy.
The withdrawal method is risky by: Farah
The withdrawal method (also known as the pull-out method or "coitus interruptus") is probably the most risky method of trying to prevent pregnancy.
It just doesn't work very well. It is a pretty unreliable method of birth control that often leads to an unplanned pregnancy. Many parents will tell you that they tried this method and ended up having a baby anyway.
Some people call it "Reproductive Roulette" because it is like gambling. It is difficult to do it perfectly so a lot depends on just being lucky with the timing.