I have a hidden stitch in belly button, what is the worst that can happen if it is never removed?

had a TT about 10 months ago & noticed a black stitch that is left in my belly button area. When I try to grab it with tweezers it pulls but is logged even with heavy force. This makes me think that the knot is inside the belly button and perhaps skin grew over the other end of the stitch. Not able to return to my Doctor & can't find another surgeon to go behind the others work. It doesn't hurt or bother me, it's just knowing that it's there is worrisome. Will I be OK, if it's not removed?