Chrissy Teigen is ''over'' being pregnant as she is desperate to meet her son.

The Sports Illustrated model is heavily pregnant with her second child, a baby boy, with her husband John Legend - with whom she has two-year-old daughter Luna - and she's getting tired of waiting for her little boy to arrive, especially as she has known from day 11 that she is pregnant as she underwent IVF treatment.

Venting her frustration on Twitter, she wrote: ''Happy pregnant Chrissy is gone. meet OVER IT Chrissy. Wanna hold my boy let's do thisssssss ... It feels worse for me because with IVF you know *so* early. I mean I knew I was pregnant at 11 days in. Crazy. [sic]''

The 32-year-old beauty - who married the 'All of Me' hitmaker in 2013 - previously defended the couple's decision to have a child via IVF.

Addressing criticism on Twitter, she wrote: ''Since this is coming up again, I said our next baby would be a boy because that is the embryo we have left. A boy. So. Yeah. [sic]''

Subsequently, one Twitter user said: ''Did you give it a minute to try naturally or are you avoiding 'the act?'''

But Chrissy again took umbrage, revealing she'd spent years trying to conceive naturally.

She explained: ''Hi Linda, thanks for asking, you complete witch. I tried for about 9 years. Anything else, let me know! [sic]''

Chrissy previously admitted her second pregnancy has been a lot harder than the first time around.

She said: ''Your second pregnancy is harder because you have a kid already.''

John added: ''You have to divide your energy between raising a kid and carrying one as well.''

However, although they're looking forward to meeting their bundle of joy, the couple are concerned about how well Luna will adapt to having a sibling.

John, 39, said: ''Luna's gonna be an issue. I think she'll probably have some growing pains because she's currently running the house right now. She's used to being the centre of everything right now so we'll see how she adjusts to sharing the spotlight.''