*wearily* Didn't you teach DADA? There are any number of... Read up on the theory. Look into how that soul shard can be neutralised or contained if it's still inside you, and the Animagus prep work sets it off. Don't attempt the spirit induction by yourself -- have someone you trust with you in case the worst happens. And, in fact, if it worries you so much, look into tests that can be done -- and there are tests that can be done -- to see if it's still there at all, and then have someone perform those tests. *shrugs* Or reconsider becoming Animagus.
*in a much nicer tone of voice, since his irritation is residual Snape-related irritation, and not genuine irritation with Q* Look. Either there's something still there, and you shouldn't even think about the Animagus transformation until that's been dealt with. Or. There's nothing there, and nothing to worry about. I don't know which it is. If I were you, I would find out.