Libby Trickett breaks "world record" swimming 1km at 35 weeks pregnant.

Former Olympic swimmer Libby Trickett isn’t done breaking world records.

Over the weekend, 33-year-old four-time Olympic gold medalist swum one kilometre for a charity event at 35 weeks pregnant and she’s sure (we’re all sure) that’s a definite, kick-arse world record qualifier.

“I think I unofficially broken the world record for the 1km ocean swim done by a 35-week pregnant woman,” she laughed speaking to Seven News following the Noosa Summer Swim on Saturday.

Trickett, who is pregnant with her second child, cheered as she ran out of the water.

“It’s a very specific record but you know, we go after it,” she said.

It’s a feat that echos tennis champ Serena Williams winning the Australian Open while pregnant in January last year.

Listen: Libby Trickett speaks about miscarrying a child. Post continues after. 

Trickett retired from professional swimming in 2013. Before that, she represented Australia in three Olympic games – Athens 2004; Beijing 2008; and London 2012.

She is a former world record holder for 100 metres freestyle; 100 metres butterfly; 50 metres freestyle; and 200 metres freestyle.

Trickett has a two-year-old daughter, Poppy, with her husband, fellow swimmer Luke Trickett.