i dont know if i have cancer

I have 1 larger testicle and I have had this for a while but not my entire life, I don't know when exactly but probably near 6th grade I noticed and I am 16 now. There is a very light pain that comes once in a while but back to the sizes, my right testicle is twise the size of my left one and my right one, I can feel it much harder than my left. My left feels so light and odd. I've have done so much research and I don't know if I have testicular cancer cause this have been going on for years and I only show 3 symptoms the size difference, the dull pain, and my larger one feels heavy. These have been doing this for so long I don't know why I'm now getting worried. I've been going to my physicles but my doctor has not been checking my "area" for any abnormalities I'm to afraid to ask my parents to take me cause I'm afraid of what he might say but if he just checks during the physical I would figure all this out. I also have an extreamly embarrasing issue... I. Learned EVERYTHING when I was very little and I hate to admit this but I started masterbating (masturbating) when I was in 4th grade. Well I didn't know about lotion or anything so long story short I have streach marks on my penis and I'M ONLY 16. I love my life but I feel like these problems are keeping me back from getting a girlfriend, from having sex. I'm not saying ill have sex at this age but I defently won't if I can't help myself and I can't seem to help myself. I need help, please help

[Julia M Aharonov, DO]

You must show this to your pediatrician at your next visit. This should not be ignored. I know it might be embarrassing to talk about to your parents, but it has nothing to do with masturbating. Tell them that you need to see your doctor and make sure that you show it to him/her. You may need to be referred to a doctor called urologist, who will need to further examine you. This may be nothing, or may be something that needs to be fixed. But it certainly should not be ignored.
Good luck.