The 26-year-old renowned for her skinny frame sparked rumors after being photographed with an apparent baby bump. Now it has been claimed she has undergone a series of pregnancy tests which have confirmed she is expecting. A source told Life and Style Weekly magazine: "Nicole recently underwent a series of tests, including blood and urine screenings, which confirmed she is pregnant." Last Wednesday - just days after her alcohol-fuelled Memorial Day barbecue - Nicole was photographed outside a reproductive clinic. She is said to be going on a special diet for the sake of her unborn child. An insider said: "Nicole’s determined to get healthy for her own sake and the baby’s." ‘The Simple Life’ star’s representative has refused to comment on the reports. Nicole, the adopted daughter of singer Lionel Richie, is currently dating Good Charlotte front man Joel Madden and the couple are reported to be engaged. She is facing a possible jail sentence after she was arrested for DUI (driving under the influence) last December. She pleaded not guilty at a preliminary hearing but the police who arrested her claimed she told them she had taken the painkiller Vicodin and smoked marijuana. Nicole will be jailed if found guilty as she has a previous conviction for heroin possession.