Lump at the back of my neck!

Ok so today I was getting my hair done and my stylist noticed a lump at the base of my neck close to my spinal cord. I got home and let my SO inspect it. When he touches it its tender but other than that it doesn't bother me. My next doctors appointment isn't until September 22nd. Do you think I should make a separate appointment to get it checked out? And have you heard of anything like this?