Jones said she has been having some trouble breathing as her pregnancy reached 29 weeks and has begun feeling contractions from all the movement, the Austin (Texas) American-Statesman said Thursday.
"I'm really surprised with as far along as I am that they have any room to move at all, but they do," said Jones, whose expected due date was not reported.
More than 25 doctors, nurses and medical staffers will be on hand at Seton Medical Center in Austin, Texas, for the birth of Jones' quintuplets.
Jones' husband, Ethan, said he has been shocked by how calm his wife has been throughout the entire pregnancy. The couple already has a 4-year-old daughter.
Ethan told the American-Statesman his wife "has such a calm about her. It's been pretty phenomenal."
NBC reportedly holds celebs hostage to Jimmy Fallon's show
Aaron Carter is still in love with Hilary Duff