Mila Kunis keeps forgetting she's pregnant.

Mila Kunis

Mila Kunis

The 32-year-old actress is set to give birth to her second child later this year but she has admitted she has to keep reminding herself she has a little one growing inside her because she's so distracted with her and her husband Ashton Kutcher's 21-month-old daughter Wyatt all the time.

She explained: "With [my first pregnancy], I could tell you precisely what she was developing, and what stage it was ... but [with] the second one, I'm running after a toddler or I'm working, so I'm like, 'Oh that's right, I'm pregnant.' "

The brunette beauty even gets a mind-blank when it comes to remembering how far into her pregnancy she is.

She added: "The other day, someone asked me how far along I was and I was like, 'I have no idea'. I was like, 'I can tell you when I'm due, and then I can do the math.' "

Meanwhile, although she regularly forgets she's expecting another tot, Mila has no qualms about the baby's arrival as she knows Ashton, whom she married last year, will be very hands on from the moment the little one is born.

Speaking on 'Live With Kelly!', she said: "He's [Ashton] an incredible father. There's not even a question. You know some men -- and it's OK -- it takes them a little bit of time to adapt to having a baby and feel comfortable. Wyatt came out, and two seconds later he had it down. He's swaddling and changing diapers. He's incredible."

And Ashton - who was previously married to Demi Moore and acted as stepfather to her three daughters, Rumer, Scout and Tallulah, with Bruce Willis - previously described parenthood as the "greatest thing ever."

He said: "It's legitimately the greatest thing ever."