It's not really what a French speaker would say. You could say "je ne suis pas sûre de ce que ça dit sur moi", that would be a literal translation. If I was in the same context (for example I image I just declared having a collection of Doctor Who memorabilia and realized it might make me look childish or geeky or what), I think I would say "ça en dit long sur moi" (It tells a lot about me) or "ce n'est pas ce que tu penses" (it's not what you think it is) or " oups, de quoi j'ai l'air maintenant" (oops what do I look like now). You see, the expression "I'm not sure what that says about me" has not quite been adopted.

Je ne suis pas sûr de ce qui est dit sur moi :)

"on peut dire : "je suis pas vraiment sure à propos de ce qu'est dit sur moi