Reports surfaced late last month that Khloe, 33, has her first child on the way with the Cleveland-based NBA star.
Although Khloe has yet to publicly confirm her pregnancy, she's been dropping hints on social media along with her half-sister Kylie Jenner, who is reportedly expecting her first child as well with new boyfriend Travis Scott.
Khloe has always wanted to be a mother but has just been waiting for the right time.
When married to her ex, Lamar Odom, Khloe admitted she allowed him to think they were trying to get pregnant, when in reality, she was just pretending.
Khloe has said their situation wasn't the best to bring a child into, as the former NBA player had been doing drugs at the time and allegedly cheating on her. (Khloe and Lamar split in 2013 but their divorce wasn't finalized until December 2016).
Since discovering she's pregnant with Tristan's baby, Khloe has maintained her healthy lifestyle.
"She's hungrier than ever," one insider told Us, adding that the Revenge Body with Khloe Kardashian host eats "smaller meals throughout the day" and is doing "more cardio" but "less intensive" workouts in order to stay fit while eating for two.
Khloe reportedly visited a specialist at Cedars-Sinai Medical Center in Los Angeles for her 20-week checkup on October 9.
Khloe has been very happy with Tristan, 26, since they began dating in September 2016 after allegedly meeting on a blind date set up by one of her friends.
"Marriage is definitely in the cards," the insider told the magazine. "They are just waiting for the right time to move forward. Khloe doesn't want to rush into anything."
Khloe revealed on the Season 13 finale of Keeping Up with the Kardashians that Tristan would ideally like to have five or six kids with her. The athlete is already dad to a 10-month-old son named Prince from his previous relationship with Jordan Craig.