May be nothing. (Ghost?)?

Okay so awhile a go I was at home, while my mom,her boyfriend, and my little sister went to church and I stayed home. I was downstairs on the computer when I heard footsteps upstairs, thinking nothing of it I was sure that it was just my older sister waking up, except she never came downstairs so I just shrugged it off. Later my mom and everyone came home and I was like what's up with chelsea she hasn't been downstairs yet, and my mom told me that she had to work at five in the morning and she wasn't home. that didn't scare me, last night my mom was on the computer and I had just gone to my room upstairs and as soon as I turned off the lights and crawled into bed I heard a voice talking to me, but i forgot what it said I was to scared and hid under my blankets*like a baby* was I imagining it out of no where or did it happen anyone want to talk to me?