Drew Barrymore daydreaming about wedding

Drew Barrymore is concerned that she does not "have it together" regarding her wedding plans.

The 36-year-old actress got engaged to beau Will Kopelman just a month ago but she feels under pressure to have everything organised.

In an interview with Good Morning America, Barrymore said that she is happy to take things at a slower pace.

"We're trying to figure it out," she told host Robin Roberts.

"I think everyone expects you to kind of know right away what the plans are."

She added that her friends were more excited about it than she was and making her feel that she was way behind schedule.

"I'm like, oh goodness, it just happened a month ago! Do I not have it together or is it ok to keep daydreaming?" she questioned.

Barrymore started dating the art consultant in 2010 and she was content being surrounded in the positivity that came with getting engaged.

"I root for his happiness and people's happiness and this is a really positive story and positive time and I like positivity, I'm drawn to it!" she said.

Barrymore also told the TV show she felt like she had been stabbed with a knife while scuba diving in the frigid Alaskan waters for her new movie Big Miracle.

In the film, she plays Rachel Kramer, an environmental activist who launches a worldwide campaign to free a family of whales trapped in the Arctic Circle - and for one scene she had to plunge into the ocean.

Barrymore admits her attempts at authenticity underwater were instantly met with excruciating pain.

"The director of this film, Ken Kwapis, he had us in Alaska on this ice flow, we felt like we were working in a snow globe theatre... I got to swim in freezing cold Alaskan waters with harbour seals...

"It felt like knives going into my body. It was insane. They told me the temperature was 34 degrees (Fahrenheit, 1.1C) and I was like, 'That doesn't sound so bad.' Then you get in and you're like, 'Ouch.' I'm very bad at pretending or faking things, I really do want to transport myself and sort of believe in whatever scenario I'm in."

But Barrymore insists the experience wasn't all bad - she was fortunate enough to meet the heroes behind the real-life 1988 rescue operation.

"We worked with people and families who have been in Alaska for generations, whose parents were involved in the rescuing of the whales... It was great."

- AAP