Colorado field searched as police investigate pregnant woman's 2013 disappearance

Police searched undeveloped land in Pueblo, Colorado on Wednesday for clues in the 2013 disappearance of pregnant Kelsie Schelling.

"Search efforts have resumed today utilizing a K-9 to assist in the search for clues in the search for Kelsie Schelling," the Pueblo Police Department tweeted.

Schelling was carrying her ex-boyfriend Donthe Lucas' child when she disappeared, according to KKTV. Pueblo police have called Lucas a person of interest in the case.

Officers did not find anything while searching the undeveloped land, authorities told the station. A Monday search also aparently failed to turn up any clues.

Last month, police announced they had searched the backyard of Lucas's former home in Pueblo. Evidence was recovered that wasn't a body, authorities told KDVR.

Schelling's mother has said her daughter vanished not long after texting Lucas an ultrasound photo, according to the station.

Lucas had asked Schelling to drive from Denver to Pueblo, and she was last spotted at a Wal-Mart, KDVR reported. He allegedly used Schelling's card to take out $400 from an ATM and drove Schelling's vehicle to the store's parking lot, the report said.