Starting 3 Days Ago (and Never Before In My Life),

Starting 3 days ago (and never before in my life), it feels kind of like my phone is vibrating in my pants pocket (but I am not wearing any pants and I'm nowhere near my phone). It's pulsing (not steady), possibly in rhythm or associated with my heartbeat, again similar to a cell phone vibration. It feels like it is probably originating in the left side of my scrotum, but could be in the left groin -- it's a little difficlut to pinpoint the exact spot, but seems like the scrotum. It isn't painful or throbbing -- no more so than a phone vibrating -- but it hasn't really stopped ever since it started. Possibly just some nerve endings firing or spasming for reasons I don't understand -- nothing happened to trigger this; it just started on Friday, but I'm concerned because it hasn't just gone away on it's own. Any idea what this is or what I should do?