Today I've been having intermittent sharp discomfort in one of my testicles. There's no swelling. Any thoughts?

See answer. Periodic, self-limiting, mild pain in testicle(s) affects most men at some point in their life. If unassociated with any noticeable swelling or palpable lumps, likely of clinical significance and iikely to resolve within 1-3 days without treatment though an otc NSAID (e.g. Ibuprofen) may be helpful. Often related to mild inflammation or congestion. Persistent pain or swelling requires evaluation.