One of the most commonly used methods of birth control throughout the world is called withdrawal. It means withdrawing the penis from the vagina before an ejacualtion or orgasm occurs. This can be a fairly effective technique if used correctly and consistently. There are several possible problems:

• Some sperm leak out before an ejaculation. Maybe only 1% or 2% of the total, but that can be 10 or 20 million! Of course, it only takes one.
• It takes a lot of discipline on the part of the man to withdraw soon enough every time.
• Withdrawal provides very little protection from sexually transmitted diseases.
• Nature did not intend sex to end this way.
• Sometimes it's messy.
• Often it's not much fun.

Withdrawal is better than nothing but not as good as any other method of birth control.

The most common side effect of this method is pregnancy