Suicidal thought when not even suicidal?
I recently had something really strange happen to me: After getting done some tough and brain hurting physics homework(that was very frustrating but not depressing) I noticed I still had my pocket knife on my desk which I usually put away after taking it with me to my normal life (for when I need it if I'm working) and all of a sudden this thought in my head came up and felt like my brain was telling me to hurt myself with it. I'm not too sure if it was actually linked to the knife but instead knowing it could do damage. I instantly grabbed it and put it far away in my room in a cabinet. I don't know why I had this thought and I'm pretty sure it isn't normal and I'm not even suicidal or hurting myself.
I'm pretty sure this isn't normal but what causes it? I might talk with one of my parents about it. I will definitely talk to them if it keeps coming up.
Sorry if this question disturbed anyone...