Kim K shows off  pregnan... curves/www.twitter.com/eliudpro

She's been doing her best to keep her changing figure under wraps since announcing her pregnancy last month.

But it seems the time has finally come for Kim Kardashian to display her growing bump in all its glory.

The 31-year-old star, who is expecting her first child with boyfriend Kanye West, opted for a tight Lycra outfit to show off her new curves as she headed home from a late-night gym session in Los Angeles on Wednesday night. 

Showing her changing figure: Kim Kardashian shows off her bump in a black vest and leggings as she heads home from the gym in Los Angeles

Kim wore a pair of tight black running leggings, a fitted vest top and a grey zip-up top for the workout session, topped off with a pair of pink trainers.

And while Kim is doing her best to stay fit and healthy during her pregnancy, she admitted to fans on Twitter that she was feeling tired and apprehensive about hitting the gym.

She wrote: 'Was so lazy but had to get that workout in! I'm so not a night workout person.'

Kim, whose baby is due in July, recently admitted she is terrified of piling on too much weight during her pregnancy.

She recently wrote on Twitter: 'Can't sleep & I'm googling double chin exercises! I'm petrified to get one.'

'Was so lazy': Kim admitted it was quite a struggle to do a workout so late at night

Tired: Kim wasn't wearing much make-up after a long day on a photoshoot

Kim's gym session came after she spent the day with her sisters Kourtney and Khloe doing a photoshoot with Ellen Von Unwerth for their Kardashian Kollection clothing range.

In some sneak peek photos from the shoot posted on her younger sister Khloe's Celebuzz blog, Kim's bump was invisible as she showed off her curves in a white dress.

Kim returned from a break in Paris this week and has since been promoting her new E! series Kourtney and Kim Take Miami.

Back at the gym: Kim was spotted at Tracy Anderson Studios in Studio City, CA, on Thursday 

Focused on fitness: The star has kept up a regular work-out routine during her pregnancy

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