I have the flu (i think), my right side abdomen hurts and my right testical hurts. Should I be worried? Thank you

Yes. The flu doesn't make your testicles hurt. Why do you think you have the flu? Is it because you have a fever and ache all over? If so, that could be just due to the fever. Fever and testicular pain means you may well have epididymitis or some other such infection and you may need antibiotics. Go see your doctor. I hope you are feeling better soon.