Keshia Knight Pulliam's Husband Files for Divorce

Keshia Knight Pulliam's pregnancy just got complicated -- her ex-NFL husband, Ed Hartwell, is divorcing her ... one week after she announced she's expecting.

Hartwell filed for the split Monday in Atlanta, and according to the docs Keshia is contesting his petition ... so we can safely assume she ain't happy.

"The Cosby Show" kid just revealed on July 18 she was pregnant, but Hartwell has some doubts he's the father. He told YBF.com -- which first reported the split -- "Right now, the only thing I want is a paternity test for the baby."

They only dated for 4 months before getting married in January of this year. Hartwell was previously married to Lisa Wu and appeared on 'Real Housewives of Atlanta.'