I Have A Swollen Gland On The Left Side Of

I have a swollen gland on the left side of my neck, not under the ear but in front left of throat. No sore throat or ear aches. Woke up yesterday that way with a fever and body aches. Feel fine today but still swollen and whole shoulder sore. Never had a swollen gland there before. What would cause this? I'm having kidney stones removed next week and worried about this now. Only hurts to move my neck because of the lump. Thank you for any ideas of a cause and could it interfere with my lithotripsy next week? Linda