I have a light green line of bruising through the center of my scrotum

I have a light green line of bruising through the centre of my sack which when comes to the bottom opens up and covers both ball,I don't really have no pain but sometimes my right testicles tends to hurt and then sometimes my left? It's been going on for 3 days now and I  Don't want to go to the doctors but could anyone tell me what this could possibly be and how to cure it?

thanks