Thank you all for the replies!
I was just wondering as I am in my 20s and had my vaccine and wasn't asked! I got the impression she thought I was a lot younger than I was so I was wondering if that was why I wasn't asked but it seems some women aren't asked. It did say in my handout about pregnancy so I guess they presume as you have read the handout and are consenting to have the vaccine without telling them you are pregnant first that is confirmation in itself that you aren't pregnant.