What is this?

I have this lump in my lower right abdomen. It is 1 cm in size. Its been there for as long as I can remember. I first noticed it when I was 11 or 12YO. Im 15 now. It has never grown. It has never hurt. It is EXTREMELY mobile. I have one on the left side to except slightly smaller. My parents say they are lymph nodes. It isnt hard but its not squishy either. Im an athlete and between school and everything else, I workout and train about two to four hours a day. When I noticed that bump when I was 11 or 12, I was just starting to get tall and thin (I was chuby back then). Im 6' 3" and 195 lbs. It is not noticeable when I look in the mirror. It doesnt stick out at all. I show no symptoms of any type of cancer. No night sweats, fevers, loss of appetite, weight loss, etc. I do sweat a little at night around the collar every once in a while but thats because I sleep with three blankets and have my door closed. Only one member, ever, in my family has had cancer and it was because she smoked.