Lifeguard Celeste Smith, 19, was last seen four days ago at a friends house before saying she was going home to take a bath.
Two friends last saw her in Gasking Street in Plymouth on Tuesday afternoon.
Julie Smith has told of the frantic search to find her daughter who said she would be staying at a friend’s house for the night just before she vanished.
Police have launched a “high-risk” search for Celeste and are concerned for her welfare.
Julie, 52, said she is “terrified” and emotionally appealed for the safe return of her daughter, the Plymouth Herald reports.
She added that she had “no idea” her daughter was pregnant until Friday, three days after Celeste went missing.
Julie, a therapist of Saltash, Cornwall, said: “We are desperate for her to come home.
“I last saw her on Monday and she was fine. She was telling me about her plans for the week and about meeting up with friends.
“We have no idea where she is, nothing at at all. This is why it’s so terrifying. There has been no contact from her at all. It’s very out of character.”
Speaking about the pregnancy she said: “Obviously, by her actions, she is worried about it or scared.
“I just want her home. We would just be delighted to have her home.”
The 5ft 5ins teen, who is of medium build with brown hair, is being sought after by friends and loved ones.
Her best friend, James Johnson, 20, made an emotional appeal to find her, saying: “I just want her to come home.”
He said: “I know she has had problems with her ex-boyfriend and she found out she was pregnant on Monday.”
Some reports suggest Celeste was last seen on a stagecoach bus on the day she went missing.
Celeste is said to have learnt about her pregnancy on Monday after splitting from her boyfriend last month.
Friends said she isn’t coping well with the news, with pals saying “her head is in a mess”.
A spokesperson for Saltash Police said: “Celeste, you are in no trouble. We are concerned for you and want to ensure you are okay. Please get in touch.”