The increase in size is likely due to bleeding into the node itself. This is one potential “complication” of the biopsy. I would put pressure on the node, and contact the doctor/hospital where it was done as soon as you can.

Is there pain or inflammation around the site? Have you checked your temp? Could be just normal swelling, but probably ok if there is no severe pain, redness, purulent discharge or fever. Call the doc if you feel something is wrong. If it isn’t life threatening, you can wait until business hours.

regardless, the prudent thing to do is notify or schedule an appointment with your physician.