STURGIS, SD (AP) — A South Dakota woman who recently gave birth to triplets says she didn’t find out about her pregnancy until she went to the hospital with what she thought were kidney stones.

KOTA-TV reports Dannette Giltz, of Sturgis, gave birth to the healthy triplets on Aug. 10.

Giltz says that despite having two other children, she did not know she was 34 weeks pregnant. She says that when she started having pains, she thought it was from kidney stones, which she has had before. Doctors told her she was actually in labor — with multiple babies.

The triplets were born within four minutes. Each weighed about 4 pounds (1.8 kilograms).

The babies’ names are Blaze, Gypsy and Nikki.