Pregnant Khloé Kardashian Says Her ‘Life Changed’ When She Met Tristan Thompson

Khloé Kardashian can’t stop gushing over her beau, Tristan Thompson.

The reality star, who is pregnant with her first child with Thompson, shared a sweet tribute to her boyfriend on Instagram Monday with a throwback photo from her 33rd birthday party this summer.

“The day I met you, my life changed,” she captioned the black and white photo booth snap of the duo kissing. “Thank you my love!”

While Kardashian, 33, has yet to officially announce her pregnancy, multiple sources previously confirmed to PEOPLE she and Thompson, 26, are expecting a boy together — due to arrive in early 2018. This will be Kardashian’s first child, while Thompson is also dad to son Prince Oliver, who turns 1 this month.