Joel Madden may not be the father of Nicole Richie’s unborn child, according to celebrity tattles.

The National Enquirer claims that there were four men in Nicole’s life before she found out that she was pregnant and that ‘The Simple Life’ star will not know for sure who fathered her child until the potential baby-daddies undergo paternity tests.

“Nicole recently underwent a series of tests, including blood and urine screenings, which confirmed she is pregnant.”