This will be the Keeping Up With The Kardashians stars first child. Thompson already has a 10-month-old son named Prince Oliver from his previous relationship.
It has only been a few weeks since news broke that Kardashian was expecting, and as PEOPLE also confirmed, the star 'couldn't be more excited.'
'Yes, Khloe and Tristan are expecting and they are absolutely thrilled,' a source told the publication. 'This isn't something they were in a rush to announce to the whole world, and it's only been in just the past week or so that they've felt comfortable telling most of their inner circle.'
Kardashian's pregnancy news came days after sources confirmed that Kylie Jenner and boyfriend Travis Scott are expecting a baby girl.