Condom
Condoms are popular for several reasons. They are inexpensive and can be bought without a prescription by either a man or a woman. They can be bought at many locations, and they are easy to use (once the couple learns how.) They have no health-related side effects for either the man or the woman, and they are one of the few types of birth control that also reduce the spread of infections.  If the couple decides to have a baby, they can stop using condoms at any time and begin trying to get pregnant with no delay.