Lymph nodes in the groin have been sore and swollen off and on the past few months. gyn did a cbc, urinalysis and metabolic panel -- everything normal. does that rule out cancer or anything serious?

No: Enlarged lymph nodes can occur from many different conditions. Lymph nodes commonly enlargen with infection; however, cancer is always suspected with persistently enlarged nodes. Please, go see a surgeon and have a full work up as this could be serious. The blood work you had done cannot rule out "anything serious".

To rule out: The normalcy of those tests are encouraging and provide good prognostic indicators of a decreased "disease state." but, the definitive diagnosis and gold standard to rule out any pathology of lymphadenopathy that persists despite treatment of any possible infectious cause is biopsy.