About 3 days ago I started to experience a slight uncomfortable pain in my testicles, I though I'd simply had sat on them or something but today the pain got slightly worse. It's nothing unbearable but it is quite annoying.

I felt around and on the back bottom of my right testicle is a fleshy lump which hurts when I touch it. That testicle doesn't really hurt on it's own, like I said only when I touch the lump.
I'm only really feeling constant pain in my left testicle and above it in my pubis area.

I'm sure this isn't a STD because I'm 17 and i've only had sex with one girl who was a virgin and that was near a month ago.

I'm getting quite worried as I don't really have the nerve to go to the doctors alone, so i'm gonna go once my GF is back from holiday which is on Saturday.

I'm thinking it might be some sort of infection though as I've had an infection under one of my teeth before but the pain was coming from the other side of my mouth. Maybe i'm just clutching at straws fearing it may be cancer, but a friend told me pain is good as that is uncommon with testicular cancer.

Can anyone shed some light on what this could be so I can do a bit of research on it to calm my nerves?
And is it stupid of me to wait to see a doctor? Or should I just suck it up and go see one?

Thanks for any help.

Al.