Suggest Treatment For Swollen Lymph In My Armpit

I'm a male, late 30s. I've got a slightly painful (to touch and stretch) swollen lymph node in my left armpit (come to think of it, I think it was swollen a month or two ago and went away) and have had a headache on and off over the past two days/nights. Started in my sinus cavity and worked its way to my forehead. Should I be concerned? See my PCP? Thanks.