Why do I Rock So Much

Yes, I am 13 female and I have a problem. I rock. Infact, as I type I am doing it right now. So, I have grown up with this habit. I rock in place stand, sittinv, and I used to rock while walking without me even noticing half the time in K-3. I am asking this now because on the 7th I had gotten laundry. Instead of folding it, it took 3 days to finish because I could not stop rocking and I had to sleep. I could rock for 2 hours to my music and only fold like 3 pieces of clothes. I don't know if this is a stim, adhd, or mental disability that's undiognosed. I have tried to stop but my body is actively seeking this movement. In school it's harder to sit still when I am listening to music. It's like a battle everyday. I have not been diognosed(Unless I havr not been told) with autism or anything on the spectrum. The only thing I remember that might a cause is my brother saying something to my sister about me having metals in my head that got removed. I don't remenber the full conversation as 1, J was in a different room. 2, I was actively crying at the time when my brother took her to the other room and had the vague conversation. But why wouldn't my mother tell me something as inportant as that? Advice?