I am a 25yr old female who has had a hard lump deeper in shoulder above collarbone- for the past year how often is this cancer ?

I never took it seriously untill I went to the doctor who is ordering a CAT scan. Wouldn't I be sick by now if it was cancer, she says it is where a lymph node is and the research I have found online all seems to point to Hodgekins. Is there anything else it could be? Also that shoulder seems to pop in and out sometimes is this related?

Thank You so Much-