It is bound to happen to me yet. I noticed a roughness to my right middle fingernail last week. Took me a few minutes before I realized what it was. I have a needle mark not quite all the way through my nail and a scratch where I moved out of the way before it pierced my skin underneath the nail. Somehow I don't remember it exactly. I remember a pinch. Luckily no blood.
Sorry for your finger. Hope you heal soon.