I have a swollen right testicol which sterted about 3 days,but it has started to reduce to its nomal size without medication.could this be fine?

NO: this could be a testicle infection ( orchitis)- Go directly to the ER or local UC center.- Do not ignore these symptoms. Go now!

Should see Dr: Most common cause of swollen testicle is an infection of the epidididymis and adjacent testicle which is called epididymo-orchitis. In men under age 35 the usual causes are the STD's Chlamydia and gonorrhea. You should see a physician and have tests for the above STD's and then treatment. On occasion a man can have epididymo-orchitis that is not infectious.

Get checked: You didn't comment whether your swelling was painful or not. I suspect you have a hydrocele which is rather benign and doesn't need immediate attention, especially since it is improving on its own. But problems that damage your testicle can cause swelling as well. So you need to get checked while you still have swelling in order to get a more accurate diagnosis. Hope that helps.