On an online application to join the New Zealand equivalent of the US Army Reserves, it asked me my gender. I put female.
Because of this, the form ajusted itself and later asked in the medical section: "Have your periods ever been irregular".
I was stumped.
I could've answer "Yes" as in, I don't have them, so that's rather irregular or I could've answered "No" as in, they have never been irregular, since I've never had one.
In the end I selected "No" since it would cause less problems.