Fashion designer Nicole Richie is worried the the Grammy award winning singer Justin Bieber will get her younger sister Sofia pregnant.

“Nicole is freaking out! She’s worried Sofia will wind up pregnant and alone. She’d taken a home pregnancy test that came back positive, but then took two more and both were negative,” a source told the National Enquirer.

Meanwhile, according to another source, Richie has been fuming after knowing Sofia’s relationship with Justin since the start, reports

“Nicole is flipping out right now over the fact that her sister Sofia is dating Justin Bieber. She told Sofia that she is just setting herself up for disaster and it has caused a huge rift between the two sisters. Sofia told Nicole to just mind her own business,” the insider said.