Actress Carey Mulligan and Marcus Mumford are believed to be welcoming her first child at the end of this year

Move over Kim Kardashian, it looks like there might be another celebrity baby bump in town.

Carey Mulligan is rumoured to be pregnant with her first child with her Mumford & Sons frontman husband Marcus.

The actress, 30, has been noticably rocking what looks like a small baby bump on the red carpet recently and now American magazine Us Weekly is reporting that she is due to welcome her first child at the end of the year.

A source told Us magazine: ‘They weren’t planning on announcing, but she hasn’t stopped working. Everybody around her is being very supportive.’

Carey and Marcus have one of showbiz’s sweetest love stories. The couple were childhood penpals. They lost contact until the power of celebrity brought them back together.

The actress, 30, revealed that they still like to write letters to each other.

‘I think they’re becoming a lost art form, which is very sad. To have a love letter from someone, to hold it in your hand and know that you can keep it for your whole life… well that’s an amazing thing,’ she has said.

The couple wed in Somerset in 2012 – Marcus’s vicar dad John married them – but they are notoriously private about their relationship. In a recent issue of Vogue she said: ‘Marcus is the only thing that’s mine that I can keep totally away. So I try to.’

Her close friend Sienna Miller has spoken about their idyllic life together though.

‘They have chickens and a dog, and roasts and friends, jams by campfires,’ Sienna said. ‘It’s sort of idyllic. Marcus can headline Glastonbury and Carey can be nominated for however many Oscars, and then they come back to their farm, and they’re in big woolly jumpers and funny hats, raising piglets. It’s an amazing balance they’ve managed to strike. I can’t wait for a little baby to come along.’