Kristin Cavallari misses her children "a lot".

Kristin Cavallari and Jay Cutler

Kristin Cavallari and Jay Cutler

The 29-year-old fashion designer is forced to travel for work and yearns for her six-month-old daughter Saylor, and sons Camden, three, and Jaxon, two, when she's away.

She said: "I think the hardest part of being a working mom is that I miss my kids a lot. I live in Chicago, but my work is always in New York or LA, so I always have to travel for my job. That usually means I'm gone for a couple of days at a time."

Kristin - who wed the kids' father Jay Cutler in 2013 - admitted it was a shock when she embarked on having a family because she was "naturally selfish" before but now finds it difficult to find time for herself

The former star of 'The Hills' said: "When you finally have kids, you realise how selfish you are. I think we are naturally selfish beings. When you have kids, that can kind of be a shock at first. I think just trying to make time for yourself is very hard. Especially now that I have three, finding that time can be very difficult."

But the blonde beauty wouldn't change her situation for the world - because her life is now filled with love.

She told Modeliste Magazine: "The most rewarding part about having kids is there's just so much more love in your life. I finally feel like I have a real identity. I feel like I have a purpose here in life now. I'm a mom to these three amazing little babies and my whole world just kind of opened up."

Meanwhile, Kristen's family have suffered a lot of heartache recently after her brother Michael shockingly passed away last year but she says her children have been a beacon of support for her through the tough times.

Asked how she's coping, she shared: "I'm OK. I mean, I have good days and bad days. I've just been looking to my kids especially for strength, and focusing on them."