Hello and hope you are doing well.
Inguinal (groin) hernias can sometimes cause a dragging pain in the testis. But bilateral pain due to prolonged standing could sometimes be due to a varicocele. Varicose veins of the testis are referred to as a varicocele. It is the dilatation of the pampiniform venous plexus and the internal spermatic vein. It is known to cause poor sperm production and hence infertility. Based on the size it is classified as small, moderate and large. It is diagnosed with a clinical examination and confirmed by a Doppler ultrasonography. It is corrected surgically. Discuss these options with your doctor when you happen to meet him next time.
Hope this helped and do keep us posted.
" I have a bulge on the right side of the groin near the waistline. can this cause either of the testicles to pain?"
In short, Yes. I'm not a Dr. but I dis have Bilateral Inguinal Hernia repair with mesh June 2012. I had a bulge in the same area you describe and it did cause testicle pain. If your asking if the Hernia on your right side can cause pain in your left testicle, I'm not sure. Like I said, I had Hernias on both sides at the same time.
"the pain starts after I have stood for some time or after a walk? please advice"
You need to see a Dr ASAP so he can evaluate you and give you a referral to a surgeon. You don't want the Hernia to become incarcerated because then you can have serious problems. It can lead to strangulation (blood supply being cut off to tissue in the hernia) My advice is to find a surgeon that does many Hernia surgeries in a month. Its a fairly easy procedure (outpatient) but you will read many nightmare stories from patients having to have there hernias re-operated on from going to an inexperienced surgeon.
Good Luck