Hi, A constant dull aching pain in testes is usually caused by varicocele (abnormally dilated testicular veins), but is uncommon in this age. Testicular tumors are extremely rare. If the doctor has examined and convinced you, I think there is no scope to worry. It is common for testicles of children to pull up when someone examine or palpate that- called retractile testes- and is normal. Also, especially in chubby or overweight, penile base may be buried on to the fat tissue over pubic bone. Here it comes out if we press the base with two fingers. Still if you are so worried, you can get it examined with a pediatric surgeon, and request for an ultrasound. Also, avoid avoid tight inners and jeans. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Muhammed Aslam T. K., Pediatrician