A Greenpoint mom hoping for a natural childbirth got more than she bargained for when her firstborn arrived in the back of a livery cab.

Artist Beka Economopoulos, 37, was two weeks from her due date when contractions suddenly started Monday night and she raced to hospital with husband Jason Jones.

In less than 90 minutes, in a car in the middle of Greenpoint Ave., the couple’s little six pound daughter Mila Amie Economopoulos Jones entered the world.

“We went two blocks from the house when I yelled at the cab to stop because the baby was coming out,” Economopoulos said.

Economopoulos and Jones, 39, both activists and artists, had been holding an Occupy Wall Street meeting at their home with two female friends when the drama unfolded.

“It was really intense but then it happened so fast it was hard to sink in,” said Economopoulos. “I didn’t even push.”

As Jones received advice by phone from the pair’s doula, the team piled into two cabs to head to hospital.

But they did not get far before the baby landed in the new dad’s arms.

“The Occupy Wall Street team turned into my impromptu birth team,” Economopoulos said.

“They’re pretty psyched.”

Two ambulances and half a dozen NYPD cars swiftly arrived at the scene and escorted the new parents to Bellevue Hospital in Manhattan.

Doctors say mother and child are healthy and can soon return home.