I used to cut and stopped, and my school might find out? Please help!?

I used to cut when things got bad when I was younger, but then I stopped about a year ago. Then yesterday, someone asked me on my tumblr if I cut or not. I told the person I used to. Then, they asked another question, and in that question they told me that they are from my school, and they asked if I would be worried what people in my year would think of me. I replied telling them that I have stopped cutting and have not cut for more than one and a half years, and that when I did cut, I got help and everything is sorted out, and still is now. I told them that I am happy, and I have put the past behind me.

Considering the fact that our school is quite protective of its students, the student that asked me that question might tell the counsellor about my old habit of cutting and I don't want that at all. Should I just tell the counsellor myself my worry and tell her that there is nothing with me now? What should I do?