Over half of all teens in the United States have had sex by the age of 18 and most use protection, according to the National Center for Health Statistics.

An estimated 55 percent of males and females, ages 15-18 years old, have had sex and about 80 percent used some form of contraception, according to the most recent data from the National Survey of Family Growth conducted by the NCHS.

There was really no difference in boys and girls. Among female teens, 42 percent say they have had sexual relations while 44 percent of boys says they have had sex.

A small percentage of teens say their first sexual experience was with someone they had just met. A majority say their first experience was with someone that they were "going steady" with at the time.

The good news is most were using protection. The most common form was the condom followed by birth control pills.

Among teens who say they have not yet had sex, the main reasons for abstaining were religious beliefs or moral values.