There are many ways you could interperet this thought. For one, I think that even people of whom don't self harm may think this to themselves (though that is slightly unlikely).

As you are a self harmer though, I am thinking that maybe that thought could be related to a thought of/urge to self harm.

I know this may be frightening for you - the first thing to come into your head was of a self harm nature. What I recommend you do is speak your T about this thought. It isn't crazy or anything. It's just because you have urges to self harm that it's sometimes at the back of your mind. And certain things to do with skin or where you cut can bring that thought forward.

Sorry you are going through tough times. Urges SUCK.

Have some PC Hugs!