Why you shouldn't worry about Kate's pregnancy on 'This Is Us'

LOS ANGELES, Calif. – Even the cast and crew of "This Is Us" knows the notoriously heart-wrenching show can't be all tears, all the time. 

Chrissy Metz, who plays Kate Pearson on the series, spoke on the set of NBC's hit family drama about one of this season's storylines  that's making fans especially anxious: her character's pregnancy. 

It's not lost on Metz how upset fans would be if Kate loses her baby. Series creator Dan Fogelman "specifically said, 'I think people will kill us,'" Metz said.

Kate has faced a rocky road to her current pregnancy. A miscarriage rocked her and  then-fiance Toby (Chris Sullivan) in Season 2, and much of the first half of this season dealt with the couple's fertility struggles and their difficulty undergoing in-vitro fertilization. It's only in recent episodes that Kate and Toby have seemed happy about their upcoming arrival, revealed in December to be a boy. 

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"Her pregnancy and the potential of a birth is one of the three main parts of the rest of the season," Fogelman said. 

Metz says she roots for her character as much as fans do. Fogelman told her "'it cannot be all terrible awful things for Kate and Toby.' And I was like, 'That’s right!'" Metz joked. And without explicitly confirming the pregnancy will have a happy ending, Metz hinted at one. "It’s not going to be easy, but there is joy at the end of it all."

That's not to say that Kate's problems are over, even when it comes to the pregnancy.

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"There’s some really emotional stuff coming up that nobody saw coming," Metz teased. "I don’t want to delve too deep into it, because I wouldn’t want to give anything away. It’s not what you’d expect, but it’s going to be really challenging for people to watch."