Suicidal thoughts as in thoughts about suicide, or as in actually seriously contemplating suicide as an option?
If the former, than yes, I've had (and have) many "suicidal thoughts," but I've never been anywhere near killing myself.
I dunno if the thoughts are abnormal or what, probably it would be unhealthy to brood on them much, but they've never scared me. I've wondered why people commit suicide, what it must feel like to be in such a state mentally, if there is anything that could drive me to kill myself and if so what and how would I do it. I've liked some really dark poetry, and was very absorbed in Sylvia Plath's novel "The Bell Jar" while I was reading it and for some time afterward. I've never had that kind of depression, but somehow I could empathize with the main character very well. This is probably due more to Plath's excellent writing than anything. And yeah, there have been a few other short stories and fictional things about suicides that really grabbed my attention and interest.
And that is my history with morbidity and "suicidal thoughts." But it's been far from an obsession, more like a recurrent curiosity. I believe I'm a very happy person and quite committed to staying alive for as long as possible.
If you are having suicidal thoughts that are troubling to you, I would say you should definitely talk to someone. Take it seriously, you probably wouldn't be worried if there was no reason to be.
If it's just idle curiosity, I'd put it down to being an emo NF.