greetings friend, having the stitch stuck in there is probably not a problem. It can lay there for years and not causing any problems set some local inflammation, if you are not having excessive pain or redness
or swelling and not getting any signs of infection then I would not worry about it. Probably the stitch will come out eventually or form a shell around it which is harmless. It does not need to be medically removed but cosmetically if it bothers you it might.I hope that this is helpful and have a good day.