oncologist prediagnosis?

Hi! I'm a little bit freaked out about what's going on! For the last few months my doctors suspected I had lymphoma. I had a lymph node removed (not the first to swell, but the easiest to access) for biopsy and it came back cancer free. This was months ago, and since it came back cancer free, no one went any further in trying to diagnose me.
Since more lymph nodes are flaring up, and the ones that have been swollen have increased in size. My doctor is referring me to an oncologist. Is it normal to see this doctor before diagnosis? What could I expect?
They don't treat unless they are absolutely sure it is there, right?

[iam1butterfly]

Referring you to an oncologist seems like a reasonable approach because you're
having significant lymphatic activity which would suggest that some abnormality
is triggering your immune system to manifest the symptoms that you described.
This doesn't necessarily translate into a Cancer diagnosis; only, a suspicion.  
It's more likely that your doctor wants to "rule out" Cancer as an underlying cause.
And, a specialist (an oncologist) is the best person to make such a determination.