The incident took place on Sunday night when the woman's husband, a driver, was not present at the house, Fatehgarh Churian police station SHO Rajesh Kakkar said.
The accused identified as Harpreet Singh knocked at the victim's door and forcibly entered the house at knife point and threatened her and her two children of dire consequences, he said.
He later raped the woman and fled, he said.
A case was registered against Harpreet Singh by the police after the victim's medical examination confirmed rape.