Kirsten Dunst is at the centre of a pregnancy riddle. The stunning actress and long-term boyfriend Jake Gyllenhaal have sparked rumours they could be expecting a baby after they were seen looking at pre-natal vitamin supplements in a Los Angeles supermarket. The star couple were spotted examining a box of New Chapter Organics Perfect Pre-natal pills in Hollywood's Whole Foods market last weekend, according to America's In Touch Weekly magazine. Onlookers claimed they even asked a member of staff about the benefits of the vitamins, which New Chapter say increase physical stamina and aid emotional well-being. Kirsten and Jake, who recently laughed off wedding rumours, were reported to have split last year. But it was later revealed the pair had concocted stories of a break-up to take the heat off their relationship. The Hollywood couple started dating after being introduced by Jake's actress sister, Maggie Gyllenhaal, who co-starred with Kirsten in Mona Lisa Smile. Jake recently confessed his love for Kirsten, saying: 'She's the only girl for me.' Kirsten, who has previously dated her Spider-Man co-star Tobey Maguire, also appeared to be smitten, saying: 'I am really happy and in love.'