Not quite sure where this should go but a few years ago I had two piercings in the back of my neck, I had them for a few months until I knocked them and they became quite painful so obviously I took them out.
The only thing now is that every mow and then I get a lump that appears there. It's quite painful and is often really itchy but will disappear after about an hour - obviously something I cant go to my GP about as I dont know when it will show up and when it will go.
If it were permenant it may have been sscar tissue but that sounds unlikely. I would guess there's a small chance a tiny bit of the jewelry is lodged there creating minor inflammations periodically.
I myself have two, constant, small lumps towards the lower of my back either side of my spine. I've been told and through a google search found that they are quite normal and nother to worry about, yours may be similar.
If you're really concerned then check for them eevry 1-2 weeks and when they appear go see the doctor, they'll tell you straight up if there's anything to worry about