Discomfort And Pain In Testicle. Urine, Blood, Sonogram Tests Normal. Doctor Suspects Bubble In Testicle. Correct Diagnosis?

Hey, I'm 17 yearold male. About 4 days ago I began feeling discomfort on my left testicle, it radiatiated towards my inner thigh onto my calves a bit aswell. My testicle doesn't really hurt, just felt weird and mild ache. This morning i began to feel a mild burn aswell as my scrotum mildly.I thought it was testicular torsion;So I rushed to the hospital. My doctor gave me a urine test, blood test, physical test, "cough, cough", & phonogram I beleive its called? Those mechanisms doctors use to check pregnant women bellys. Anyways, everything came out fine, I was okay and normal. He says it is an air bubble inside my testicle, & that it's very normal for males to get this, also that I could have pulled a muscle on my groin. My question is :
1.Could all these symptons mean I have an airbubble I'm my testicle? Does it explain every thing I am feeling?
I'd like to add that my urine is perfectly normal, no pus nor blood, no burning while urinating, I masterbate often, but I have only done it once while put through this discomfort. After i masterbated, I felt a lot better, slept great, but this morning, an hour after I woke up, my left testicle mildy burn like i said before. Another question I have is:
2. Can all the test they gave me really prove that there is nothing wrong?
When I walk or stand up, it feels a lot better, sometimes forget about the discomfort. It seems when I lay down or sit, the feeling comes back. All the doctor provided me was multrin.
It seems when I smoke marijuana, I feel it more, because I beleive I think about it to much, and freak out. This morning I was high on marijuana when I experienced the burning, but I still feel it mildly sober too, only when I'm high , I feel it a bit more. Also:
3. Why am I feeling in my leg do much? Inner thigh, calves?
I provided as much information to make sure I'm getting a direct anwser so thank you for reading this! But I am very worried still, you know that feeling if you ever felt it, you want anwsers & help. I hope you reply back!