How can a guy find out if he is infertile?

Okay well, I was just wondering if a guy can find out if he is infertile without having sex. Like if you ejaculate in a condom, and then hold a light under it (Kinda like you can do when you hold a light under your finger nails) can you see the sperm swim? I have a feeling that I will not ever be able to procreate. :(