The birth of football star Tom Brady’s son with ex-girlfriend Bridget Moynahan threw off Gisele Bündchen when she started dating him, reports.

“In the beginning you’re living this romantic fantasy; you’re thinking, this can’t be true, it’s so good!” the supermodel, 28, tells Vanity Fair. “And then, whoops — wake-up call!”

The pregnancy made her “question at times — ‘Should I stay here? Maybe you should work this out,’” but she says in the end, it “was a blessing, because otherwise I don’t think I would have known what he was made of, and he wouldn’t have known what I was made of,” she says.