What Causes Persistent Pain In Testicle?

I ve had testicle pain for the past few days and its been annoying. Its not severe; just mild and niggling. I am able to move round and carry on activities and what not. I think it might be important to note that I was working out at home about a week ago (and did not work out in months prior). I did cardio and ab workouts. First few days I was sore in my legs and abs, and days later I started feeling the pain in my testicles. Could it be workout related?If it is workout related is this a groin strain? Is a groin strain supposed to be the same as testicle pain? I m not really sure. Also I can t really pinpoint the location in the testicles, but its just that general area that feels sore I guess. I don t think there is swelling either.I ve been looking online and some other stuff like cancer is supposed to be painless. I also looked into possibility of kidney stones (which can cause testicle pain), but I heard the pain associated with stones is severe and mine hasn t felt like that.Also for the record I am not very sexually active, and have not been for about a year.Also if it helps, when I get an erection the pain goes away at that time. It also is not present when I sleep but returns sometime after I wake up in the morning.Also I m no expert in checking for lumps or whatever, but I don t feel anything out of the regular there. Also I am able to like touch around in that area with no specific pain. Basically the pain seems really general, and I cant pinpoint a certain testicle or area where there is a bruise etc.