The search for missing pregnant mom Jessie Davis has been called off because of bad weather.

Afternoon rain and thunderstorms caused Thursday's search for the 26-year-old, conducted by about 1,500 volunteers, to be canceled for the rest of the day.

Before the bad weather hit, cadaver dogs searching for missing pregnant mom were put on the scent of a fresh mound of dirt in a waste area at Highland Park Street NW and Aultman Avenue, in Canton.

Stark County sheriff's Chief Deputy Rick Perez told reporters Thursday that agents and deputies were on the scene investigating the find, but he had no further information. Perez said he would provide updates when he had them.

"Jessie's still missing. Until we find Jessie, we're going to keep on searching," Perez said.

A sergeant with the Springfield Police Department called for the dogs around noon Thursday when the mound was discovered. Five dogs and their handlers are concentrated in an area off Highland Park, where a lot of trash has been dumped.

The search party with the group was asked to wait on a grassy hill roughly 50 feet from where the cadaver dogs are concentrated.

Craig Cassidy was among the volunteers to discover the mound of dirt.

"We came across a mound that looked as though it had been freshly dug up," he told FOX News. "They brought in five or six dogs." He said the indication was that "there was something there," but he hasn't been back to the site since.

One of the volunteer searchers, a 10-year-old boy, found a green rug in the vicinity with a white pattern. The rug seemed to have been there for a lengthy period of time.

"We're very emotional," Whitney Davis told reporters at a news conference. "We're under a lot of stress ... I am just trying to keep it together."

About 1,500 volunteers gathered early Thursday to assist in a new search for Davis, many of them total strangers to the 9-months-pregnant woman's family.

On Wednesday, for the second time in three days, investigators searched the home of the man who fathered Davis' 2-year-old son and unborn daughter, although authorities have repeatedly said Canton police officer Bobby Cutts Jr. is not a suspect.

Perez told reporters Thursday that while Cutts' home was searched the previous day, he was not arrested or detained during that time. He declined to comment on reports that Cutts had been read his Miranda rights.

A local law enforcement official told FOX News that Cutts was read his Miranda rights during the first search of his home on Friday, and he waived them.

When police returned Wednesday with a search warrant, they laid out a probable cause for scouring his home again, which was that they were seeking evidence of aggravated murder and kidnapping, the source told FOX News.

Perez also said Cutts didn't work the night of June 13, when Davis was last heard from. He reiterated that Cutts is not a suspect, but an "associate" and an "acquaintance" of Davis'.

Sheriff's investigators and FBI agents carried out more than a dozen white cardboard boxes, a few brown bags and three large black plastic bags during a search that lasted more than three hours.

A legal order allowed investigators to obtain some of Davis' cell phone records, which are being reviewed, Perez said at a news conference Wednesday.

Cutts, 30, told The (Canton) Repository he had nothing to do with Davis' disappearance, and that he has slept little and had no appetite since she vanished.

Cutts, who also has two children with his wife, Kelly, said they are separated but have not filed for divorce and that his wife knew he had a relationship with Davis.

He said he last spoke with Davis at 8 p.m. on June 13, about 90 minutes before she last spoke with her mother.

Cutts' mother, Renee Horne, told the Repository that agents at her son's house were looking for Davis' cell phone and a quilt missing from the Davis' home.

Horne said FBI agents questioned her son twice Wednesday, and read him his Miranda rights during the second interview. Investigators also took Cutts' two cell phones, Horne said.

“I feel confident with all the law enforcement agencies working on the case," Whitney Davis told FOX News. "We are happy with them and we know they are doing the best they can right now. They can’t share every lead with us.”

The volunteers searching for Davis formed a line about two football fields long before they began combing the neighborhood for clues to her whereabouts.

"We just really need to find her," her younger sister Whitney Davis told FOX News on Thursday. "I feel very anxious. The first search we did was nerve-wracking. I hope we find some kind of lead or some kind of clue."

Texas EquuSearch, an internationally active search team, brought in sonar equipment to northeast Ohio to check ponds and a remote-control airplane equipped with a camera to look for any sign of Davis.

"They're going to help us find Jessie, hopefully, bring her back safe," The Associated Press quoted Whitney as saying.

Some of the volunteers waiting for the search to start brought their dogs or children. Many sipped donated bottles of water, and one man had a hiking stick. People continued to join the line along a sidewalk to sign up at a fire station to help.

"I think every single rock will be turned over on this search," said organizer Tim Miller, who runs the internationally active search team Texas EquuSearch.

Miller had expected about 200 volunteers Thursday and said he was a bit overwhelmed by the turnout. His team also brought in sonar equipment to check ponds and a remote-control airplane equipped with a camera to look for any sign of Davis.

Whitney Davis wore a T-shirt with her sister's picture and the word "Missing" in red letters.

“She’s my sister and it’s breaking my heart that we don’t know where she is," she told FOX.

Lisa Hoffman, who works for EquuSearch and has been involved in many searches, said she had never seen such a large turnout.

"It's crazy. This is a high-profile case," she said.

Jessie Davis, whose baby is due July 3, was last heard from in a phone call with her mother on June 13. Two days later, her mother checked on her home in nearby Lake Township and found it in shambles, with the furniture overturned, a comforter missing and her 2-year-old grandson wandering around alone.

The little boy told investigators: "Mommy was crying. Mommy broke the table. Mommy's in rug."

A pool of bleach was on the bedroom floor, and the contents of Davis' purse were scattered in the kitchen.

Whitney Davis said the little boy does talk about his mother.

"He misses her," she said. "He asks where she is."

Miller said all hope has not been lost.

"We're holding onto that hope that maybe she's still alive out there," said Miller. "That would be the greatest thing in the world, but realistically, we know after a period of time that that normally doesn't happen."

Miller started EquuSearch his 16-year-old daughter, Laura, disappeared in Texas and was found dead 17 months later. Funded through donations, the group offers search-and-rescue training and uses specialized search equipment to help recover human remains around the world and search for missing children. It has worked on hundreds of missing persons cases, including the 2005 disappearance of Natalee Holloway, 18, in Aruba.

"We're probably looking at somewhat of a miracle in this case," Miller said. "We also know if that person is deceased out there it's very important we find them as quickly as we can find them so they can determine cause of death."

Meanwhile, authorities said DNA tests would not be finished until next week on a newborn girl left on a porch about 45 miles away from Davis' home. Authorities are trying to determine if the infant, less than 24 hours old when it was found Monday evening in Wooster, is related to Davis.

A bottle and can of formula left in the basket with the newborn were sent to be tested for fingerprints or any other evidence.

On its Web site, the FBI lists the case as a kidnapping. But FBI spokesman Scott Wilson in Cleveland said the label is standard whenever foul play is a possibility, and the agency doesn't know if Davis was abducted or not.

The FBI is offering a $10,000 reward for information leading to Davis' whereabouts. EquuSearch added a $5,000 reward.

Thursday morning, the volunteers gathered at the firehouse near a sign that read, "Pray for Jessie," to help EquuSearch's efforts.

"My heart goes out to them," said Lisa Dillon, 47, who took a vacation day from her state job to aid in the search. "I just want to help."

FOX News' Jeff Goldblatt and The Associated Press contributed to this report.