Was I really supposed to be in the HP Universe?

So, I somehow got transported into the body of a baby. Oh, and the baby is the (nonexistent) twin sister of our favorite character, and so I'm flipping the whole story upside down. Quick question: am I supposed to be here or is this a rip between space and time! Well, doesn't matter. I'll just make sure Harry doesn't have to lift a finger against Voldemort! He's my little brother!