Sex & Reproduction

Knowing what happens during your menstrual cycle will help you understand how the different methods of birth control work. A woman has two ovaries, one on each side of the uterus. Each month, one of the ovaries releases an egg into a fallopian tube. This is called ovulation. It usually occurs about 12–14 days before the start of the menstrual period.

What Does NOT Work

The following things do not stop you from getting pregnant:

  • Douching does not prevent pregnancy—Squirting water or any other liquid into the vagina after sex does not kill sperm or prevent pregnancy.
  • Plastic wrap instead of a condom does not prevent pregnancy—Plastic wrap or a plastic bag can tear and let sperm escape.
  • Urinating right after sex does not prevent pregnancy—Urine does not pass through the vagina so it does not get rid of the sperm.
  • You can get pregnant the first time you have sex.
  • Having sex in a special position does not prevent pregnancy—No matter what position you have sex in, if the penis enters—or comes close to—the vagina, you can get pregnant.

During sexual intercourse (sex), the man's penis goes into the woman's vagina. This can lead to ejaculation. When a man ejaculates ("comes"), his penis releases semen, which contains millions of sperm. If this happens during sex, the semen spurts into the vagina.

Sperm in the semen can swim up the cervix and into the uterus and the fallopian tubes. If a sperm meets an egg in the fallopian tube, fertilization—joining of an egg and sperm—can occur. The fertilized egg then can travel to the uterus and attach to the lining. Once the fertilized egg has attached to the lining of the uterus, the woman becomes pregnant, even if it is her first time having sex.

Birth control methods can be used to prevent pregnancy. Some methods also prevent STDs. You may have heard about "tricks" you can use to not get pregnant. Do not depend on them—they do not work.