It's outside my apartment door, and I don't know what to do

My partner and I have been together for half of a year, and I spend a fair amount of time at his apartment, and I'm still adjusting. There's so many little noises, like doors closing, footsteps in the room next door, the television on in the apartment below... I could go on. There are a few noises that I could live without hearing, but that's just me, otherwise they're kind of soothing.

it was around nine pm when the knocking started. My dogs picked their heads up, but fell back to sleep a minute or so later. I walked over to the door and peeked through the peephole and into the hallway, there was a young girl in a white dress standing outside my door. Se looked like she was around five years old. I was about to open the door, but a wave of dread washed over me the second my skin made contact with the brass knob.

Something wasn't right. I looked through the peephole again to see that she was now staring back at me; those eyes... They were bottomless black pits I got lost in, but then recoiled and backed away from the door as quickly and quietly as I could. The knocking started again, as though there were something much larger than a five year old behind it this time around. My dogs start barking and growling, snarling at the door with their teeth bared. I pull them away and into the bedroom, brandishing a knife I found in the kitchen.

The knocking. Doesn't. Stop. She's still out there, pounding on the door. I've thought about calling the police, but I know that I would sound crazy if I told them the truth. Or worse. The little girl in the hallway would tell them that I was her mother and locked her out and wouldn't open the door. After that I'd be dead. Deader than dead, even. She won't stop. I don't know what to tell my boyfriend, maybe try to convince him that I need something from the market, but then again, what do I ask for and how do I know he'll get it for me without question? He'd ask why, then proceed to tell me that the market is closed by the time he gets off of work.

I can't think of a way to keep him safe, and I don't know what I'm going to do if she gets in. There is no lock on the bedroom door, I can't break the window, I can't take the dogs with me even if I could break the window. I don't want to do that. I keep thinking about my options: weighing them against each other, but no matter how I slice it, I won't be able to save the dogs. I can't do that, I won't let that thing get them.

The knocking stops. That's almost worse than the knocking. I don't know what's going on, but I know that I'm not leaving this room, no matter what. I could run to the kitchen and get the salt out of the cabinet, but then I remember we don't have salt. For a brief moment, I want to laugh as a scene from Supernatural passes over my mind's eye, but I stifle it, not wanting that thing to know where I am. I should be studying right now. I should be making dinner. I should be doing so many other things than this right now, but I don't dare move from my spot.

Everything is silent, with the exception of my panting dog, but then my blood freezes; I can hear the door opening despite the fact that I know I locked it when I came back from getting the mail earlier. I don't move, I don't breathe, I just hold still and wait for the nightmare to be over. Footsteps, small and deliberate, draw closer to the bedroom door, and my dogs start growling again. Before I can do anything, the door opens slowly and the face of the little girl is revealed. She's smiling with a mouth of far too sharp teeth, and far too wide to fit completely on her face, her black eyes glittering with delight. With a voice far too deep and menacing for a human to possess, she says the last two words I'll hear in my short life:

"Found you."