On last week's episode, Ted, played by Josh Radnor, proposes to Chalke's character, Stella.
So what does the actress have to say about the Internet rumors that her character is the "mother" in the show's title.
"I don't know - they don't tell me anything. I just show up," Chalke tells Early Show co-anchor Julie Chen. "It's such a fantastic show. It's so well written I can see it going on for year and years. The cast is fantastic."
"How I Met Your Mother" is a comedy about Ted and how he fell in love. The series is narrated by Bob Sagat as a grown up Ted, through flashbacks from the future.
"I play a dermatologist who removes a tramp stamp - Ted had a butterfly tattoo after a drunken party night tattooed on his back, and so I removed that," Chalke explains. "I got a call at the very last second to come be on the show. They said can you be here in the morning, you're playing a dermatologist and can you bring your lab coat? So I had my "Scrubs" lab coat and they put a pocket protector over the Dr. Elliot Reid patch."
Before her stint on "Scrubs," fans may remember Chalke as the second Becky on the sitcom "Roseanne."
"I actually just bumped into Becky No. 1 on the street yesterday afternoon," Chalke said. The actresses were also reunited with other "Roseanne" castmates at the TV Land Awards, which paid tribute to the sitcom.
Outside of TV, Chalke says she always wanted to be an athlete and on a sports team. She says she finally "settled for the most under attended sports" of race walking and shot put at her high school in Canada.
"I actually made it to the provincials in race walking," she said, reminding Chen that it is an Olympic sport.
She also has a penchant for pumpkin. "It's my favorite food," she says excitedly.
Chalke is also giddy because for the first time in eight years, she will be heading home next week to celebrate Canadian Thanksgiving.
"We were always doing 'Scrubs' during Canadian Thanksgiving," she said.
"How I Met Your Mother" airs Mondays at 8:30 p.m. ET on CBS.