Any infection can cause lymph nodes to swell, and they don't have to swell evenly. Usually, when you have a cold, the infection is symmetrical and so are they lymph nodes, but this isn't always the case.
As for your infection spreading, I think you'd feel worse if that were the case, but the ENT should be able to tell you more definitively.
Thanks for replying
Its been 2 months almost since i first noticed the node. Do you know of any causes which makes it swollen for so long? Its also not painful.
My dentist said i had caries in many teeth can this cause the node to swell?
I'm not sure if a cavity would do it or not. Something as simple as acne or razorburn could do it, though. I actually have a bit of a lymph node that I can feel in the same location (there isn't one on the other side that's palpable), but I don't think there's anything wrong with me. It's possible that some lymph nodes are just different. The ENT should be able to tell you if that's actually true.