What Causes Lump On Neck And Sneezing?

Hi felt a small kind of lump on my left side of my neck 2 to 3 days ago when I woke up. It does not hurt. But I can feel it there. Have had allergies more than usual. Sneeze a few times. Like sinus allergies. About a month or so ago, went to doctor for flu and sinus . Gave me antibiotics for 4 days +cough medicine.