“No one believes me when I talk about this, but I’m really maternal,” the actress says in the new issue of W.

“I worry that because I’ve always wanted [kids] so much, as the world goes sometimes, I won’t be able to have them, even though I would be able to provide them with such an amazing environment,” Fox, 23, and is known for her perfection, except maybe for her, err, feet, says.

The Transformers star adds: “And you know, the people who hate kids and don’t want kids always end up having 50 of them.”

Fox does have a child in her life, however: Kassius, the seven-year-old son of her boyfriend actor Brian Austin Green. Although she and Green (together for five years) recently called off their engagement, they remain together, and share a home with Kassius.

The star — recently Razzie-nominated for worst actress of 2009 — confides that “I have no confidence, and because of that I’m always second-guessing myself.” For fear of reading harsh reviews of her acting and off-the-cuff comments, she avoids going online.

Save for a high school friend back in her native Florida, Fox counts few female friends — especially within Hollywood. “I especially don’t trust girls in this industry, because it’s incredibly competitive, and I’m just not interested,” she says.

But in revealing new interview, Megan Fox reveals a more vulnerable side by admitting she lacks self confidence and says she doesn’t look classy in underwear.

The many admirers of the 23-year-old actress may beg to differ – but it seems Megan has a very clear idea about what kind of look she evokes in a pair of smalls.

Her latest sponsors might not be impressed, but if they had read any other of her occasionally wacky comments they certainly couldn’t claim to be surprised.

Speaking to W magazine as part of a new photoshoot, the Transformers star said: ‘There are some women you could put in underwear and photograph them, and it looks really classy and it doesn’t necessarily provoke a pin-up image.

‘But with me it does, immediately, as soon as I”m in underwear. I’m a Vargas girl, she added referring to Alberto Vargas, a famous Peruvian painter of Sixties pin-up girls.

Megan, who has been dating former Beverley Hills 90210 boyfriend Brian Austin Green since 2004, also talked about her lack of confidence in acting and modelling.

She said: ‘My main weakness is nerves. I have no confidence, and because of that I’m always second-guessing myself.’

But something she is looking forward to is motherhood, revealing she also has a very maternal side.

‘No one believes me when I talk about this, but I’m really maternal,’ Fox said.

‘I worry that because I’ve always wanted [kids] so much, as the world goes sometimes, I won’t be able to have them, even though I would be able to provide them with such an amazing environment.’

When asked about trust in the film industry, Fox said: ‘I don’t trust people in this industry, but I especially don’t trust girls in this industry, because it’s incredibly competitive, and I’m just not interested.’

The actress’ next film will be the thriller Passion Play, which also stars Mickey Rourke, Bill Murray and Rhys Ifans.