I think someone is in my house right now?

Well, I came home from the Vacation bible school job i voluntered for and when I went to go get my dog a treat I heard the TV on upstairs. No one is home right now but me, I went upstairs to check and the TV is off. I asked is anyone there, and I brought my dog up and I heard noises, like the house creaking and some other stuff. My dog was like on full guard, when she heard it because it was like someone was hiding and rubbing against things. I don't think I should call 911 because this might not even be real. No I'm NOT a troll, and I'm not that frightened, but I locked the doors in between the garage and my kitchen so NO ONE is getting out of the upstairs. BTW The Upstairs is where my AUNT lives. We live downstairs.