Painful swallen lymth node in neck. streptococcus test is negative. throat is not read. what could it be?

Swollen lymph node: Could be from a low grade infection such as bacterial or viral. Have you seen a dentist? Could you possibly be having any tooth problems? If you have had this swollen lymph node for a long time without resolution, it would be a good idea to see your physician for a workup. They will likely draw some blood and make sure everything looks good on that end.