Small growth under skin between testicals and rectum?

This is kind of embarring, and this is the 1st time i have ever used this service. But i was giving myself a examine in the shower the other day. And i noticed the skin between my testicals and rectum (taint) has a small pea size growth under the skin. It is very hard at the touch. Does anyone have any idea's what this could be? You cant see it above the skin you can only feel it just under the skin. Thank You