Warren faces mounting questions on another part of her personal story: Was she fired for being pregnant?

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Sen. Elizabeth Warren, D-Mass., who in recent weeks has been surging in the polls in the Democratic presidential primary race, sought Tuesday to clarify another part of her personal story that's been called into question — namely, her claim that she was fired in the 1970s for being pregnant.

Warren has long told the story of how in 1971 she was fired in the first year of her teaching job because she was “visibly pregnant.” It has been presented as a key moment in her story, propelling her toward Harvard and eventually politics.

VIDEO APPEARS TO CONTRADICT WARREN'S SUGGESTION THAT SCHOOL FIRED HER OVER PREGNANCY

But that story was cast into doubt after a 2007 interview reemerged in which she said she left the job after realizing that the education courses that she needed to take weren’t working out for her.

"I went back to graduate school and took a couple of courses in education and said, 'I don't think this is going to work out for me.' I was pregnant with my first baby, so I had a baby and stayed home for a couple of years and I was really casting about, thinking, 'What am I going to do?'" she said.

Most recently, The Washington Free Beacon located county records from the local school board, showing that the board in April 1971 voted to extend Warren a second-year contract similar to the one she held the previous year.

A few months later in June, the minutes show that her resignation was “accepted with regret.”

Warren told CBS News on Monday that her life since becoming a senator has caused her to “open up” about different parts of her life as she stood by her account. And on Tuesday, she reiterated her claims that she was pushed out, indicating that while the contract was extended in April when her pregnancy was not visible, that changed a few months later.

“When I was 22 and finishing my first year of teaching, I had an experience millions of women will recognize. By June I was visibly pregnant — and the principal told me the job I'd already been promised for the next year would go to someone else,” she tweeted.

“This was 1971, years before Congress outlawed pregnancy discrimination — but we know it still happens in subtle and not-so-subtle ways. We can fight back by telling our stories. I tell mine on the campaign trail, and I hope to hear yours.”

Speaking to CBS, she also stood by her claim of being “shown the door” by the principal.

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"When someone calls you in and says the job that you've been hired for for the next year is no longer yours, 'we're giving it to someone else,' I think that's being shown the door," she said.

This isn’t the first controversy surrounding Warren’s backstory. The beginning of her campaign was dogged by questions about her claim to have Native American heritage.

In February she apologized to Cherokee Nation for taking a DNA test to prove her ancestry — a test that an analysis found suggested she was between 1/64th and 1/1,024th Native American.

So far, other 2020 candidates have not taken aim at Warren for either controversy. On Tuesday, Colorado Sen. Michael Bennet, asked if Warren has an issue with trust, told Fox News that "we're all going to go through this X-ray of the soul" and that "the people who have been consistent and truthful about where they are, are going to stand up well."

Fox News' Paul Steinhauser and Sam Dorman contributed to this report.