Victoria Beckham is feeling the strain ahead of her catwalk show this weekend.The designer is working day and night to get her latest fashion collection ready for New York Fashion Week, but hasn’t lost her sense of humour, tweeting a picture of herself with a bag on her head. Underneath it she wrote: ‘After three hours sleep I feel like an old bag! x vb #NYFW’She had earlier hinted at her late nights to complete her latest collection - which will debut on Sunday - tweeting department store Bergdorf Goodman late last night: ‘Thank you @bergdorfs #CN £FNO! Its going to be a late night, still in fittings! Good night NY! X vb’Earlier in the evening Victoria had been at the store with Vogue editor Anna Wintour, where she helped launch Fashion’s Night Out, wearing one of her own orange dress designs.Victoria today spoke to the New York Times about why she decided to show her collection in the Big Apple rather than at London Fashion Week. For me, I lived in America, although I am British-born and my aesthetic is British,’ she told the publication.‘But I admired U.S. brands, and I wanted to follow the U.S. model. It seemed like the right thing to do.’As well as working on her fashion designs, Victoria also has four children, Brooklyn, 13, Romeo, ten, Cruz, seven and 13-month old Harper with her husband David Beckham.