BOSTON – Massachusetts Democratic U.S. Senate candidate Elizabeth Warren said Friday that she didn’t reveal until this week that she told past employers about her Native American ancestry because she needed more time to recall actions and events of years ago.

In a telephone interview with The Associated Press, the Harvard Law School professor and consumer advocate also addressed in greater detail other questions related to her family heritage, which has not been documented. She spoke on the eve of the Democratic State Convention in Springfield, Mass., where she was expected today to receive the endorsement of delegates in her bid to unseat incumbent Republican Sen. Scott Brown.

Warren has always maintained that she learned of her heritage through family lore. In the interview, she detailed further what she and her brothers had been told by their parents, the late Don and Pauline Herring.

“My mom and dad were deeply in love,” said Warren, who was raised in Oklahoma. “My father wanted to marry my mother, his parents objected, because she was part-Cherokee and part-Delaware.”

She never sought proof of ancestry, she added, because she had not felt it necessary.

“My mother was proud of who she was, and it was an important part of who she was. And my mother is an important part of me.”

Earlier this week, Warren’s campaign issued a statement in which she acknowledged, for the first time, that she had told Harvard and her previous employer, the University of Pennsylvania, of her Native American heritage, but only after she had been hired.

The key, she said, was that she never received any advantage from her Native American ancestry during her academic career.