Jill and Bill Schroeder had been married five years when they decided to have their first child.

That was November 1976 and they're still childless. And frustrated.

"I didn't believe the doctor," Jill Schroeder recalls. "I'd never heard of a woman not being able to have children. I had six brothers and sisters . . . My mother, she got pregnant real easy. I thought, 'did I do something wrong? Did I not take care of myself?'"

Sometime later this month, the Schroeders are hoping their luck will change. If all goes according to doctors' plans, 31-year-old Jill a bookkeeper, will enter a hospital here for an operation that could make her famous or merely continue her frustrations.

The operation is designed to help her become pregnant -- something doctors say is now impossible because her fallopian tubes are blocked. The odds against success are so great that physicians refuse even to quote her chances.

What they will say is that the Schroeders are among 35 couples attempting to become the first in the United States to have their children conceived with the help of the country's first "test-tube baby" laboratory.

While Jill Schroeder's operation will be a major step in American medical technology, it will not create a "test tube baby" like Louise Brown, the world's first such child born July 25, 1978, in England.

In the pure, test-tube procedure, known as "in vitro" fertilization -- which is planned for some of the 35 couples -- the ripe egg will be removed surgically from the mother's ovary and placed in a shallow glass lab dish along with a quantity of the husband's sperm.

Researchers hope fertilization will occur in the dish. About 36 hours later, after the egg has divided into about 16 cells, it will be placed in the mother's uterus. The hope is it will attach itselt to the wall of the uterus and develop as a "natural" pregnancy.

By contrast, the conception the Schroeders seek should occur in her body after a team of surgeons at the tiny Eastern Virginia Medical School here remove an egg and implant it in her uterus, bypassing her blocked falliopian tubes.

If they are successful, the egg will be fertilized there by Bill Schroeder's sperm, giving the couple their dream -- an otherwise natural pregnancy and child.

The Schroeders' is an operation that has not occured in the United States. To date there have been only six successful implants anywhere in the world and two of those resulted in miscarriages of deformed fetuses.

But the failures have done little to dampen the enthusiasm of the Schroeders, selected from among 3,00 couples who have applied to the medical school's clinic in hopes of conceiving a child here. Researchers say there are between 250,000 and 666,000 couples in the United States who could benefit from their program -- an indication of how widespread are infertility problems.

For many like the Schroeders, the numbers are small comfort, given the difficulty of accepting their own inability to reproduce. A year ago, Jill Schroeder became so depressed she "couldn't look at a baby. I'd start crying on the street, or I'd hurry up and run to my car and cry there. At one point we had three or four babies in our families and it was hard for me to pick them up or anything."

The Schroeders had been trying to achieve pregnancy for about 10 months before Jill Schroeder started "getting worried.

"I'd figured I'd be pregnant by March or April of '77. I had it all calculated. I was sure I was going to have a baby by the end of '77 or beginning of '78. I wondered 'what's wrong? It is him or me? What's going on here?'" she said.

After a trip to Goshen, Ind., to visit their families for Christmas, their Norfolk doctor arranged for Bill Schroeder to have a sperm count. The findings: no apparent problem with his reproductive system.

Jill Schroeder then began a series of examinations, tests and hospitalization, learning finally that she suffered from endometriosis, a build up of tissue in the fallopian tubes that prevents the ripe egg from reaching the uterus.

"The doctor couldn't say why, and I just felt real empty," she said, remembering the cold February morning in 1978 when her gynecologist gave her the news.

A surgical attempt to clear her tubes failed, and in December 1978 X-rays were taken after dye had been injected into her body.

"The one side looked fairly normal," said Bill Schroeder, "except the dye wasn't going anywhere. And the other side, the dye had dissipated over a wide area. [The doctor] felt that side was in pretty bad shape" -- apparently not connected to anything -- "and the other side wasn't too bad, except it was still blocked."

By January 1979, the couple was told by their doctor they had three basic options: "We could try surgery again, but he said there was less than a 10 percent chance that would work; we could adopt, or we could forget it."

Adoption was "just something I can't do," said Bill Schroeder, a civilian auditor for the Navy. "I'm not positive in my own mind I could treat an adoptive child like my own."

"I'm not 100 percent sure either," said Jill. "I think there'd always be that little bit of doubt. If I can't have my own, I'll do without . . . and cry about it."

Another faint possibility held out by the doctor was the new clinic being established by the Eastern Virginia Medical School. The Schroeders were very interested.

Despite a flood of about 2,000 inquiries from desperate couples to the clinic by February, Jill Schroeder was accepted for testing in May, and the couple was told they should start making up their minds about going through with the progam.

"On the way home," Bill Schroeder said, "I said, 'We might as well start making up our mind right now, rather than thinking about it for two or three weeks . . . We've been thinking about this for a long time.' We decided we were going to go through with it."

Unsure whether insurance will pay the clinic's $4,000 price for the operation, the Schroeders have continued to drive their two 10-year-old cars and have put off purchasing a house, preferring to save the money to pay for their last chance at having a child.

The hardest part about waiting for the clinic's first attempt -- which may or may not involve the Schroeders, depending on the ovulation cycles of the various women in the program -- has been watching nervously as members of a Tidewater Virginia antiabortion group try to stop the project.

"I think they believe what they're saying," said Jill Schroeder of the opponents' claims that the program will result in the death of countless imperfect unborn children. "I just don't think they've been listening to what they've been told.

"Let them believe what they want to, but let me believe what I believe.

Give me a chance," she said.