It's no secret that Zephyr Teachout is pregnant, but on Monday she put that front and center in her campaign for state attorney general, releasing a provocative new digital ad.

The ad shows an eight-month-pregnant Teachout getting an ultrasound, asking a question about what her child's future will look like.

"And rallied against pharmaceutical and insurance companies for putting profits before people," the law professor narrates in a portion of the ad. "I'm Zephyr Teachout, and you've never seen an attorney general like me."

Up until this point, her pregnancy has not been a central issue in the campaign, largely going unmentioned by Teachout and her three Democratic rivals.

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"I think ones of the things that's really important to communicate is that being pregnant or being a parent doesn't change my own history," Teachout said at a campaign event. "It doesn't change the fact that I'm an anti-corruption expert. It doesn't change the fact that I sued Donald Trump three days after he took office."

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Many see Teachout as the insurgent outsider. She secured the endorsement of one prominent independent Monday. In a statement, Vermont Sen. Bernie Sanders said he was confident Teachout would tackle corruption.

Letitia James, the city's public advocate, held a women's rally on Monday. "Countless number of women organizations, from Higher Heights to Emily's List, have endorsed Letitia James," she said.

But she declined to weigh in on Teachout's new digital presence: "I haven't seen the ad, so I don't really have a response."

A new poll shows that Teachout has a little work to do to catch James and another rival. A new Siena College poll released Monday morning showed Rep. Sean Patrick Maloney in the lead in the Democratic primary for state attorney general, with 25 percent of the support among likely primary voters. James was just one percentage point behind and Teachout had 18 percent. Leecia Eve had just three percent of support.

Almost a third of voters were still undecided. This poll was conducted between September 4 and September 7. It has a margin of error of +/- 4.3 percentage points.

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Maloney, meanwhile, did not have any public campaign schedule Monday, three days before the election.

With so many undecideds in this race, some say it's still a toss-up, meaning anyone could win Thursday.