What does this dream mean?

It was early in the morning, my dad woke me up cause he slammed the bathroom door hard (he had to go to work) and I decided to keep sleeping. So I fell asleep again and started dreaming this scary dream. (for me it was scary cause I rarely have scary dreams or dream anything at all) I dreamed that, school was about to begin and I needed to get prepared for it. So I went in my room to look for my gym clothes, and you know how in dreams everything's messed up? so instead of getting a Gym t-shirt, I got a pillow. Anyways I heard my parents calling me, so I talked from the hallway that I have right outside my room and I replied, "No not now, I have to get ready for school" (cause they asked me if I could do something real quick) and my dad replied angrily, "NO. You're gonna do this, and do it NOW." and I left my door, a TINY bit open so I could see into the room and there was a light reflection on the door. As I was arguing with my parents, for some reason I decided to look into the light reflection and I saw this massive shadow of a lady, tied hair, big breasts, she was wearing a skirt and a sweater. and she was walking. Once I saw that, I SCREAMED (in my dreams) and ran downstairs... thats where the dream stopped. I woke up terrified, I couldnt move, I didnt wanna open my eyes, and I was home alone (except my dog) again it was 4:33 am and this dream got me SHOOKED. what does it mean? Does it even have a meaning?