Chrissy Teigen is shocked by just how "big" she has become while pregnant with her second child.

Chrissy Teigen and John Legend

Chrissy Teigen and John Legend

The 31-year-old model - who revealed earlier this month she and husband John Legend are to be parents again - thinks she's gained far more weight than she did when expecting her daughter Luna, 19 months, and wants her fans to be honest as to whether or not it's "normal" to have a larger bump the second time around.

Chrissy asked: "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)"

The star has had almost 3000 replies to her Tweet from followers, reassuring her she has nothing to worry about.

Medical advice states that women undergoing their second pregnancy will often find they grow bigger more quickly. This is because the muscles in the womb and stomach have already been stretched by the first baby bump.

The 'Lip Sync Battle' star announced the family's happy news in a sweet video posted on Instagram last week.

The clip showed Chrissy pointing at her stomach and asking her daughter: "Luna, what's in here?" to which the little girl replies, "Baby!"

Chrissy had previously revealed 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 ..."