Investigators say the 18-year-old victim was allowed to leave the San Joaquin Valley home on Saturday and she called police.
She says 21-year-old Richard Garibay became enraged when he found a text message from another man on her cellphone.
Investigators say Garibay beat her and used tape to bind her arms and legs while threatening her with a handgun in the Ceres home south of Modesto.
Police say Garibay's friend, 20-year-old Armando Osegueda, helped restrain the pregnant teenager.
The Modesto Bee says Garibay was arrested on Tuesday.
Osegueda is also in jail as an accessory.
