Janet Jackson Is Expecting

LOS ANGELES (CBSLA.com) — Janet Jackson is pregnant with her first child two weeks before her 50th birthday, a source confirmed to ET.

The singer will turn 50 on May 16. Last month, she announced she will be postponing her tour to start a family with husband Wissam Al Mana.

She said on a Twitter post: "My husband and I are planning our family. So I'm going to have to delay the tour. I have to rest up, doctor's orders."

USC fertility specialist Dr. Kristin Bendikson said the pop star most likely underwent in vitro fertilization or IVF, but probably not with her own eggs. That is unless she had her eggs frozen when she was in her 30's.

"The chance that a woman, who is 49 years old, will get pregnant is very low, probably less than one percent," the physician said. "As a woman gets older, the quantity and quality of her eggs goes down. Her eggs have always been there since before she was born. So those eggs are aging just like any other cell in her body."

But a woman's uterus does not age like her eggs. That means a woman in her 40's or even 50's can still get pregnant, but only with a donor's eggs from a woman in her 30's.

"You can be menopausal and use an egg donor and get pregnant," Bendikson said more middle-aged women have been coming to see her. And she wants her patients to have realistic expectations.

"I just think it's important for women to have accurate information. So that they don't change their family planing in the future based on what they see on television and what's going on with celebrities," she said.

A woman's fertility begins to decline starting around 30 years old. It takes even a steeper drop when she turns 35. Once she is in her 40's, the chances of conceiving on her own are extremely slim, the fertility specialist said.

It is not known yet when Jackson's baby is due.