Strange voices in my house

Sooo, for some years I've heard voices like, saying things to me and I ignored them bc I thought it was my mind playing with me. But last year I proved that it was real, and I want to tell the experience bc I js remembered it lol.

Sometimes I heard like my mom is calling me so clear, but when I go ask her she tells me she didn't call me, and I thought that maybe I heard wrong.

Normally my mom send me to sleep abt 9 PM and she yell from her bedroom that I have to go to sleep. Well, every night I used to spent my time doing the next day homework or studying for some test (when I was in high school, I graduated last year). So this night that was what exactly happened, I clearly heard my mom's voice saying "Come to sleep" and I replied "coming", I finished my homework and went to my mom's bedroom and she asked me "who did you reply to?" I was confused so I said "well, you", she said she never called me, she was nearly sleep but she clearly heard that someone called me too. I have to say, my mom and I live alone, there was no one in the house but her and me. 

That was how I realized that all the times I thought she called me, it wasn't her, but something else. Bc of college now I have to stay up later doing homework, abt the midnight and early morning, and sometimes I feel like someone is watching me, but maybe I'm js seeing things, idk.