A lump on the testicle could be many things and definitely should be examined by a doctor. If you're uncomfortable with a female doctor, get a male doctor. Either way, doctors are professional, have seen it all, and will not judge you, but you do what makes you most comfortable. If you're young, then talk to your parents and tell them you want a male doctor.

As for it being a varicocele, you shouldn't try to diagnose yourself as it could be many different things. Some serious that should be taken care of right away. I have a varicocele and it wasn't noticed until I had an ultrasound, because of pain. It doesn't exactly provide a lump, but it may be evident by feeling larger veins. An actual lump on the testicle that does not move, is most likely not a varicocele.

Go to a doctor and get it checked out. It's not something to self-diagnose or leave alone.