Credit Report

When offered a free credit check by TurboTax, I obliged, and entered in my information. When I got to my security questions, they were definitely someone's, but not mine. Every single one was very specific and had nothing to do with me. After trying the series of questions twice, I was locked out for 30 days. I fear someone has stolen my identity. I understand that I am young (early twenties) and don't have much credit, but that doesn't explain the security question issue that arises before a report can even be given. What do you think? and if my identity has been stolen, what is the next step?

Thank you