On Oct. 2, 2018, Chicago postal worker Kierra Coles vanished without a trace.

The 26-year-old was about three months pregnant and over the moon to have her first baby, according to her mother, Karen Phillips.

"She was so happy," Phillips told ABC News. "We just couldn't wait for her to experience the love between a mother and a child."

But five years later, there's still no sign of Kierra Coles, and her mother is pushing for answers.

"We're really not OK," Phillips said.

"It's not like I found my daughter, I buried her, and we know where she is," she said. "I don't know if she's dead or alive, being harmed. ... We have to live through this every day."

The Chicago Police Department classifies Coles' disappearance as an open but cold case.

Phillips is extremely frustrated there's been no arrests. She said Chicago detectives haven't called her with updates in over a year, and she believes the case isn't getting attention because her daughter is Black.

In response, the Chicago police told ABC News, "We are seeking any and all information in an attempt to locate her and we won't stop until we do."

The biggest update in Coles' case came last year when police released surveillance video that captured a person of interest and revealed some of the 26-year-old's last known movements.

The surveillance video showed a man -- who police said is a person of interest -- arriving at Coles' home on Oct. 2, 2018. Later, Coles and the man were seen driving away in Coles' car.

At about 10:43 p.m., Coles was spotted on surveillance video making ATM withdrawals -- the last known images of her, according to police.

Later that night, Coles' car was parked in another part of the city, police said. The person of interest was seen getting out of the passenger side, but nobody got out of the driver's side, according to police.

The next day, the person of interest was seen parking Coles' car near her home and going inside, police said. He then left Coles' home and drove off in his car.

When the person of interest was interviewed, police said he gave varying accounts of the last time he saw Coles.

Police have not named the person of interest, but Phillips believes it is Coles' boyfriend. Phillips said she hasn't heard from Coles' boyfriend since the missing persons report was filed.

Natalie Wilson, co-founder of the Black and Missing Foundation, Inc., called the lack of progress in Coles' case "very disheartening."

"Maybe [police] have information they've not yet shared," Wilson said, but "we're sitting on the sidelines waiting."

At the end of last year, there were 97,127 people in the National Crime Information Center's Missing Person and Unidentified Person Files, according to the FBI. Nearly one-third of those people -- 30,285 -- were Black, according to the FBI.

But according to the Black and Missing Foundation, the media coverage of white and minority victims is far from proportionate.

Wilson said it's up to the community, law enforcement and the media to give attention to the cases that may be overlooked.

"We have to do a better job of protecting Black women and girls," she said.

"We cannot forget Kierra, or any of those that are missing and their cases have gone cold, because their families deserve answers," Wilson said. "And with Kierra's case, there are two people that are missing -- it's her and her child."

Wilson urged Chicagoans to continue to share Coles' missing persons flyer.

"When you see a flyer, be our digital milk carton, and help these cases to go viral. Because we need to solve them for these families," she said. "They just want to be able to sleep at night."

Phillips said she'll never stop looking for her daughter.

"As long as I got breath in my body, I'm never gonna give up," she said. "I feel like if I give up, I'm letting her down again. I already feel bad that I wasn't there with her when whatever happened happened."

The Chicago Police Department asks anyone with information to submit an anonymous tip to CPDTIP.com. The U.S. Postal Inspection Service is also investigating the disappearance of its employee and said anyone with information can call the U.S. Postal Inspection Service’s hotline at 877-876-2455. The Black and Missing Foundation also has an anonymous tip line at bamfi.org.