The woman tried to end her life by consuming some poisonous substance at her Sector 12 residence yesterday, Sector 24 police station SHO Umed Singh Yadav said.
She was rushed to a hospital, where doctors said her condition was stable.
During interrogation, she told police her marriage was scheduled on December 2.
She said her fianc had sexual relations with her, but refused to the marriage. Thus, she decided to end her life, police said.