Lance Corporal Maria Lauterbach was eight months pregnant when authorities say she was killed.
ABC News is reporting test results show Lauterbach was going to have a girl.
Eyewitness News is also confirming that the Onslow County authorities sent the murder weapon, a crowbar, to the SBI lab in Raleigh.
Sources also tell Eyewitness News Lauterbach was killed on the same day she disappeared -- December 14.
Police previously believed Lauterbach was killed December 15.
The search continues for the man suspected in her death, 20-year-old Marine Corporal Cesar Laurean.
Onslow County Sheriff's Captain Rick Sutherlin says hi officer received a credible tip that Laurean may have been seen out west. The FBI believes he is in Mexico.