Unusual childhood fears?

When I was little I was extremely afraid of being murdered, especially by my mother, for no reason. I wouldn't go to sleep before she did and had a few escapes planned for if she tried to kill me. This was completely irrational since my mom is pretty much the nicest person ever. I was paranoid when we went for drives that she was planning on taking me to a field and was going to leave me there (we lived in the country). If a car was behind us I thought it was following us, and if there was only two other cars on the road, one behind and in front of us, I thought they were together planning to kill us. This was all in elemtary school. These fears stopped in about 4th or 5th grade. I'm not paranoid anymore. I told my mom and laughed about it. She said that isn't normal child fears so I looked it up and couldn't find anything. I know being so paranoid can be seen in people with mental illness but then I would still be that way right? Is there any explanation for this?