During the singer's virtual appearance on Carrie and Tommy Monday, the camera slowly panned over to show the pregnant model, 36, as Legend, 43, talked about writing love songs.
Once on camera, Teigen excitedly revealed her bump and moved her hand around her belly. She then bent down into the frame and waved to the hosts and laughed as they congratulated the couple on their baby news.
Teigen and Legend — who share son Miles 3, and daughter Luna, 6 — announced last week that they're expecting another baby together.
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In September 2020, Teigen suffered a pregnancy loss with the couple's third baby, son Jack, due to partial placenta abruption.
"The last few years have been a blur of emotions to say the least, but joy has filled our home and hearts again," Teigen captioned her pregnancy announcement on Instagram, which saw her sporting a crop top and lace underwear. "1 billion shots later (in the leg lately, as u can see!) we have another on the way."
Teigen admitted that she had fears about the pregnancy after the loss of Jack. "Every appointment I've said to myself, 'ok if it's healthy today I'll announce' but then I breathe a sigh of relief to hear a heartbeat and decide I'm just too nervous still," she said.
"I don't think I'll ever walk out of an appointment with more excitement than nerves but so far, everything is perfect and beautiful and I'm feeling hopeful and amazing," Teigen continued. "Ok phew it's been very hard keeping this in for so long!"
Teigen first revealed via social media that she was undergoing in-vitro fertilization treatments in February.
"Hiiii. I posted about it in my stories, but I wanted to let you guys know I'm balls deep in another IVF cycle to save as many eggos as I possibly can and hopefully make some strong, healthy embryos," she wrote.
"I honestly don't mind the shots…they make me feel like a doctor/chemist…but the bloating is a bitch," Teigen continued. "So I humbly beg you to stop asking if I'm pregnant because while I know it's said with excited, good intentions, it just kind of sucks to hear because I am the opposite of pregnant!"
"But also like please stop asking people, anyone, if they're pregnant," she added, before promising her followers that should she get pregnant, she will "be the one to tell you."
Legend then told PEOPLE in March that Luna and Miles "know we are trying, and they are excited."