How do I answer an HR person who asks me if I'm planning a pregnancy at the time of joining a company?

How do I answer an HR person who asks me if I'm planning a pregnancy at the time of joining a company?

I’m surprised no other answer has mentioned this: in the US, this question would be against the policy of all large employers and is highly likely to lead to a lawsuit. It implies that the employer would discriminate against you on the basis of pregnancy or gender, which courts have ruled is illegal, typically under both federal and state laws. If I were asked this question in the US, I would try to document it in some provable way, and then consult an employment law attorney. I would also raise the issue to a more senior HR person, and if they don’t express shock and promise that this is not acceptable, I would look for another company. Consider whether they would ask a man the same question, and whether a company that treats their female candidates differently will treat their female employees differently…