Cardi B is telling her side of the story in a civil trial with a former security guard … and she says she called the woman a bitch for recording her in a doctor’s office.

The “Bodak Yellow” rapper took the stand Tuesday and testified she was walking through a Beverly Hills obstetrician’s office while 4 months pregnant in 2018 when a security guard at the building, Emani Ellis, started following her and recording on a smartphone.

Cardi says she confronted the woman and they got in each other’s faces in the hallway and called each other all sorts of nasty names … including “bitch.”

CB testified things never got physical … despite Ellis claiming on the stand Monday that Cardi took a swing at her and used a long fingernail to slice open her left cheek.

Cardi says Ellis is way bigger than her and she wouldn’t try to attack her … instead, extending verbal jabs.

While Cardi said Ellis was recording her with a phone, she testified she never saw the alleged footage.

The trial stems from a lawsuit we first reported … and now the women have taken their beef to the witness stand.