Hello and welcome to the forum. You are male, I take it? You plucked it rather than shaved it? What comes to mind is perhaps you have an ingrown hair. https://www.mayoclinic.org/diseases-conditions/ingrown-hair/symptoms-causes/syc-20373893 Your doctor can diagnose this fairly easily. They may prescribe a steroid cream to aid healing, or if infected, antibiotics. I would cease plucking at this time until it is resolved. Let us know how it goes.