MADONNA is pregnant with her third child. Or is she?

Rumors are raging among Madonna’s friends that the Material Girl is getting maternal again.

They say the singer — who already has a 2-year-old son with hubby guy Ritchie and a 6-year-old daughter from her relationship with fitness trainer Carlos Leon — desperately wants another baby to patch up her shaky marriage.

“She just found out she’s pregnant,” says a source close to the star.

Madonna’s publicist Liz Rosenberg insists that Madonna is not in baby-making mode. But she’s the same publicist who denied Madonna’s pregnancy with Rocco until the star was in her third month.

Not even Madonna herself can be relied upon to tell the truth. She told Matt Lauer a bald-faced lie when she repeatedly denied in a “Today” show interview that she was expecting Ritchie’s baby — and then days later admitted she was a third of the way through her pregnancy.

Madonna’s frequent squabbles with Ritchie are the talk of the show business circuit. Yet in spite of the turmoil, Madonna is determined to keep her man, pals say. And she’s convinced a baby will help.

“She says that the period after Rocco’s birth was the happiest she and Guy have been,” said the source. “And she’s always wanted more kids.”

Agreed another insider: “Madonna and Guy have an up-and-down relationship, but what really keeps them together is the children. When Rocco was born it was the happiest day of Guy’s life and Madonna wants to give him another child.”

Even though older mothers are at higher risk of birth problems, Madonna wants another baby. “She’s 44 years old, but her body age is a lot younger,” the insider said.

“She’s had a full physical assessment and she’s in really good shape.”

Madonna’s willing to take a risk to strengthen her marriage, pals say. There has been strain between the couple since last year when “Swept Away” — the film starring Madonna that Ritchie directed — bombed at the box office.

At her birthday party in Beverly Hills, the two had such a nasty quarrel about their movie that Ritchie took off for London the next day.

“They have discovered that there can be problems when they work together,” the insider said. “But when they’re on their own with the kids they couldn’t be happier. Madonna loves the serenity and she loves to see Guy happy with the children.

“I hope this works out, for the two of them.”