Could this be testicular cancer.

Hello all, I'm  a 28 year old male from India (now in the US for PhD). I have been  having pain in my left groin/scrotum from the beginning of January. The  pain is dull and achy and after a few weeks I also started getting pain  on the right. The pain on right scrotum isn't as frequent and prolonged  as the left. I had varicocele surgery done in 2013 when I was 19 on the  left side and it recurred in a year and it was bilateral. I went to my  gp here at the university and this is what they noted each time : On  Jan 11: Normal male external genitalia. Testes are descended and are  normal size. No hernia is detected. There is no discharge, rash, mass,  or lesion. Slight tenderness in the left epididymis - no masses or  lesions noted On Jan 20:  Uncircumcised phallus.  No testicular pain/masses bilaterally.   no pain  right epididymal region.  Pain left epididymal region with either  varicocele/scarring from prior surgery. can I have cancer without a mass /lump or swelling?