Are your lymph nodes tender? If so, that's a good sign. If not, you really need to get back to your doctor and demand a biopsy. 95% of lymph node swellings are related to infections and are benign. You need to look for signs such as them being tender (good), soft (good), non-fixed (meaning it hasn't attached to other tissue (good).
I don't want to scare you, but it's not common for them to be swollen so long.
In June, 2008, 7 weeks after having my second child, I found a swollen lymph on my collarbone. My instincts took over, and 3.5 weeks later, I was diagnosed with Hodgkins Lymphoma (cancer).
Stay off the internet - it will only make things worse. Just ask the doctors for a full biopsy, not a fine needle biopsy which is often inconclusive. I have met many, many people since my Diagnosis who were in a similar situation to yours and were treated for infections. Thankfully, mine was in a suspicious place, but the first doctor I visited (my OB) was not concerned. I had to press, and despite working in the pharmaceutical industry and having access to several physicians, only a few thought it was possible cancer-related.
Please feel free to send me a private message if you'd like to know more as I've become an unfortunate expert on lymph nodes.
Good luck.