She is 15 and pregnant, a condition that until recently might have shamed her family and forced her into a home for unwed mothers. Today, instead, she is a celebrity among her peers and plans to stay in high school until the baby arrives in March.

"Sometimes I feel like there's a little nail running along inside my stomach," she giggled, patting her protruding abdomen. "It's exciting."

To many of the high school girls of Montgomery County, teen-age pregnancy has become not only acceptable, but fashionable.

"Baby chic" is how one county official refers to the recent trend.

Last year, 26 teen-agers from Albert Einstein High School in Kensington gave birth during the school year. This month, there are 10 pregnant students at Rockville High School -- the same number of pregnancies reported for entire 1978 school year.

While the county has no hard statistics on the number of pregnant teen-agers in the schools at this moment, one recent report submitted to the school board estimated that one of every 10 teen-age girls in Montgomery County will become pregnant this year.

"Yes, I'm concerned," said Rockville High assistant principal Jerry Lynch. "It's totally accepted by the kids. It's not the stigma it once was."

According to Steve Zepnick, a counselor in the county's social services department, "its fashionable to a degree. The girl will announce her pregnancy and their friends say, 'It's groovy.' As a peer group thing, it's encouraged. It means you stand out. It means you're different."

Pregnancy, many of the county's teen-age girls believe, is a sure way to gain instant adulthood.

"Getting pregnant gives teen-agers power over their parents. They use their body as a weapon," explained Deborah Hollander, a sex education consultant and Montgomery College teacher. "It is also a rite of passage, from girlhood to womanhood."

One Rockville student said recently that being pregnant gave her an identity. "I understood where I was at," she said. "You know what your position is in the world."

Mark Langlais, who heads the Rockville Free Clinic, said teen-age pregnancy "is a power trip." Within the last few months, he said, "we've had an inordinate number of pregnancy tests done here at the clinic and a very high percent of those were positive."

Langlais said the country has "pretty parks and pretty houses" but does not have a high level of health care -- especially for pregnant teenagers. "There's not a lot available here," he said. "No one talks about pregnancies here. The schools aren't going to do anything about it. The government isn't going to do anything about it. No one wants to talk about it."

Until recently, Montgomery County schools discouraged pregnant students from staying in school. But now, the girls are encouraged to attend classes, and the schools offer home instruction and alternative programs designed to cut down on the large number of teen-age mothers who drop out.

The county established a special teen-age pregnancy task force last year. The report, submitted this summer to the board of education and the county government, projected that 10 percent of the 27,448 female teen-agers in the county would become pregnant this year.

However, since no hard statistics were available on the number of pregnancies in the county itself, the report relied on national figures to compute the local projection. Several officials familiar with the report believe that the county's teen-age pregnancy rate is higher than the national average, a shocking thought to parents and teachers who believe, "It can't happen here.

The report also concluded that the county's health care services for teenage mothers "are scare and limted in scope."

"If this many kids are getting pregnant, something is missing," said Mark Tartamella, head of public school health education curriculum.

Many blame the schools for lack of sufficient birth control information. Said Tartamella: "Our education needs to be more comprehensive. We've got a way to go. I think the county is a little gun-shy."

Maryland is one of six states in the country that require sex education in the schools. However, the classes are not mandatory. Contraception is taught in grades 9 through 12. The 8th grade curriculum includes an overview of human sexuality. Many sex counselors would like to see contraception taught to 13-year-old students.

According to a recent study, a teenage girl is most likely to become pregnant within the first six months of her first sexual experience. Since adolescents are generally experiencing sex at an earlier age, counselors say teen-agers are being offered too little, too late.

In Deborah Hollander's opinion, "the schools are scared. They say sex belongs at home. But many parents do nothing."

But School Board President Marian Greenblatt, who quipped that teen-age mothers might be "makeing up for our declining enrollment problem," said teen-age pregnancy is "society's problem."

"We can't hold the schools responsible for cutting out all the ills of society," she said, adding that she has not had time to read the task force report.

The report, which strongly recommened school and community support to obtain funding for needed services, has also not reached the desk of Montgomery County Executive Charles W. Gilchrist. A spokesman for his office said last week, however, that Gilchrist was "very concerned about the problem."

Of the more than one dozen high schools in Montgomery County contacted for information on pregnant students, only two health nurses agreed to discuss the subject.

Ann Triantafillos, the nurse at Albert Einstein, said the school's 26 deliveries last year was "extremely high". Normally, she said, the school would have approximately five pregnant students. Of those 26 girls who gave birth last year, none have returned to complete their education. Most of them, Triantafillos said, are on welfare.

"We tried to get a project going for the school," she said. "We proposed a day care center, so the girls could attend classes and also wanted to have a class in parenting for the girls and boys. The school system rejected the prosposal. We didn't get the necessary funds."

While an increasing number of girls are getting pregnant and keeping their babies, counselors and health officials agree, many more teen-agers in Montgomery County are choosing abortion.

According to the Maryland Health Department, there were 2,330 abortions performed in Montgomery County in 1977. More than 40 percent of those abortions were performed on tenn-agers. Nationally, one-thrid of all abortions are performed on teen-agers, which means Montgomery County's teen age abortion rate is higher than the national average.

"Kids here should not be using abortion as birth control," said Tartamella. "But it appears to be happening."

Abortion, the counselors say, is easier for some girls to obtain than are birth control devices. It is not unusual for teen-age girls in Montgomery County to obtain three abortions a year, some counselors said.

"So much of today's life is fun," said Ann Triantafillos. "And if it's fun, it must be OK. We put a lot of emphasis on sex. This is the message the kids are getting."

What the kids are not getting, Triantafillos added, is information on the drawbacks of teen-age pregnancy. According to Planned Parenthood, babies born to 15-year-olds are twice as likely to die as babies born to mothers aged 20 to 24. The babies are not only likely to be premature and low-weight at birth, but they also run a greater risk of neurological disorders.

Carol Kaiser of Rockville, who last year gave birth to a son, said recently: "Having a child at 17 pushed me into maturity. I never dated, never went to a prom. I guess I never really was a teen-ager." Kaiser receives $202.93 in welfare each month.She decided to have a baby, she said, because she was insecure. "I could have done without it, but since it's here, I enjoy it. I have to accept reality."

Although Kaiser never completed high school, she dreams of going to college. "If I'd never gotten pregnant, I'd probably be happier," she said.

Asked to describe her current situation, Kaiser said, "Age-wise? A teen-ager. Responsibilty-wise? A mother."