Kourtney Kardashian hits the gym for grueling workout... as rumour of baby number four with Scott Disick surfaces

She's been flaunting her bikini body on Instagram and documenting her grueling workouts on Snapchat.

And Kourtney Kardashian hit the gym for a couple of mammoth sessions this week, amid rumours she is expecting her fourth child with on-off boyfriend Scott Disick.

Radar Online is claiming the 37-year-old Keeping Up With The Kardashians star is in her first trimester after giving her relationship with Scott another go.

Scroll down for video 

Working out: Kourtney Kardashian hit the gym on Tuesday for a grueling workout amid claims she is expecting her fourth child with on-off boyfriend Scott Disick

Kourtney already shares Mason, seven, Penelope, four and Reign, two, with 33-year-old Scott.

The website claims that Kourtney is so early in the pregnancy that she's only telling very close friends.

Kourtney and Scott were apparently trying to get pregnant since reigniting their romance last year, a source tells Radar. 

Low key outing: The mother-of-three was spotted out in Calabasas on Tuesday 

Make it monogram with Kourtney's Louis Vuitton backpack

Kourtney Kardashian was on mommy duty when she was spotted out and about with her oldest son Mason in LA. The KUWTK star donned a velvet wrap top with ripeed Good American jeans and a pair of Stuart Weitzman boots.

She accessorized with a mini Louis Vuitton backpack. The 'Palm Springs' bag features the French brand's signature monogram logo as well as silver hardware and leather straps in an eye catching black and red colorway.

We instantly fell in love with this little darling the minute we saw it and if you did as well and have a spare $1910 burning a hole in your pocket, click right to buy yours today.

Otherwise invest a little less in the backpacks we've selected in the gallery below.

* PRICES MAY NOT BE AS ADVERTISED

Baby on board: Kourtney has been documenting her long workout sessions on Snapchat

The duo are yet to confirm they are back together but have recently enjoyed trips to Nantucket, Miami, and Aspen together.

'They are working it out for the sake of the child and neither one of them is seeing anyone else right now' a source told Radar. 

A spokesperson for Kourtney did not immediately respond to Dailymail.com's request for comment.

Kourtney and Scott broke up in July 2015 when he was accused of cheating on her with one of his exes in Europe.

They have since remained close and committed to co-parenting their three children together. 

Not skipping a beat: The KUWTK star isn't slowing down if the pregnancy rumours are true

Ready for another one? Radar Online is claiming Kourtney and Scott were 'actively trying' for another baby after rekindling their romance last year 

Jet-setters: The duo have enjoyed recent trips to Nantucket, Miami, and Aspen with sources claiming they are 'definitely back on'

Scott has been in and out of rehab in an effort to overcome his issues with substance abuse but is said to be doing everything he can to prove to Kourtney he's over his party boy ways.

A source told E! News in December: 'They are back together and giving their relationship a try again.' 

The source explained: 'Scott's mellowed out a lot and hasn't been partying.' 

Looking good! Sources say that it's so early in the pregnancy that Kourtney is only telling very close friends. She shared this bikini snap last week from her vacation

 

The comments below have not been moderated.

The views expressed in the contents above are those of our users and do not necessarily reflect the views of MailOnline.

By posting your comment you agree to our house rules.

Who is this week's top commenter? Find out now