reported for self harm

hi everyone. just as a background, i’ve been self harming for years but have been clean for a few weeks now. the person did not have previous knowledge of me self harming. today in my class, i was running an unfolded safety clip up and down my coat sleeve. i couldn’t even feel it. i was just bored and doing something stupid, but i understand how that could look bad. my friend asked me about it and i said i wasnt doing anything. he then saw my OLD self harm scars on my wrists and assumed i was actively self harming. he didnt really try to talk to me about the situation. he went to a teacher that both of us trust & told the teacher & i was reported. my mom told me she got an email about it. i talk to this teacher often & i’m very close with them and when i went to talk with them about my school day things felt weird. my question is, is it okay or appropriate to tell this teacher that it was a misunderstanding and that im not self harming? im not angry at this teacher, as its his job and i have nothing to hide BECAUSE i was not self harming. but as i said im very close to this teacher and i feel like i cant talk to him because of what happened.