Chrissy Teigen can't believe ''how big she's got so fast'' now she is expecting her second child.

The 'Sports Illustrated' model - who is adding to her family with her husband John Legend - can't believe how big her baby bump has got recently.

Sharing a picture of herself in the mirror, where her baby bump can clearly be seen, she captioned it: ''How so big so fast (sic)''

Meanwhile, Chrissy - who also has 20-month-old daughter Luna Simone with the 'All Of Me' hitmaker - previously admitted she was shocked by just how ''big'' she has become while pregnant with her second child.

She asked her Twitter followers: ''Can someone just be honest with me and tell me if it's normal to get bigger, faster with second baby? because I am getting big, fast, and everyone's go-to is 'It's that second baby!' but they're lying. I know it. I can handle the truth just tell me. It's not normal is it (sic)''

And Chrissy had previously revealed that she would love to be ''pregnant for the rest of her life''.

She gushed: ''I feel good, I feel good, we're still trying ... I'm going for I mean hopefully in the next few years because for me I really want to just knock 'em out. That's my dream, I want to just be pregnant kind of for the rest of my life. Not for the rest of my life, but the rest of my fertile life. So we'll see ...''