Swollen lymph nodes throughout the body?

Im 16 , I have had swollen lymph nodes for a while. I noticed them in my neck under my jaw about 6 months ago , and in the side of my neck ( throat area ) about 3 months ago and in my groin and armpit about 2 months ago. They could have been there longer. They are small and painless. I had a serious of different infections before and after christmas , about 5 - 6 months ago. I had an Ear infection , was given anti-biotic's , but I didn't finish the full course. About a month later I had an upper respiratory tract infection and was given penicillin , but again like last time , I stopped taking the anti-biotics when I felt fine. I also had some viral infection in-between. I had a blood test to check for mono , but it came back negative. Any Ideas ?