Basically what everyone else has said above, but I'll add that the doctor won't exactly be fondling and gazing lovingly at your balls - he'll have something in particular that he's looking for and examine accordingly, so it shouldn't feel sexual. I had my boob checked over by a male doctor one time and it wasn't awkward like I was expecting it to be at all - he just kind of prodded around a bit in the relevant areas and it was fine.
TL;DR the handling (for want of a better word) you'll receive shouldn't feel particularly intimate, and as people have said above the doctor's seen it all before so won't be bothered by it at all.