Could The Stiffness In Neck Be Due To Swollen Lymph Node?

hi doctor, i've had a swollen lymph node under my jaw for 10 days now, it appeared suddenly one evening and it hurt for about a week. now the pain is going down but the lymph node is still there, id say about 10-12 mm size, and it hasnt changed. the dentist diagnosed me with a very mild necrotizing gingivitis about a month ago, but now my gums appear to be healthy since i got antibiotics and started treating them properly. my neck is stiff and im kind of worried. should i be?
thanks