I gave it more thought and I'm much calmer now. The doctor is the head of the oncological ward, if he suspected something sinister he surely wouldn't tell me to wait for a whole month. He reassured me that it's either nothing or a very treatable lymphoma and that makes me happy, however I still can't shake the fear that something will happen to the node during the month, like it'll get hard as stone or something. Guess it's just the nature of health anxiety ¯\_(ツ)_/¯