How hard should a hit in the balls be to cause a man infertility?
Are there any precautions or "first aids" to do when you get hit?

I have a boyfriend who used to smoke weed and I wanted to know if it can play a part in not being able to get a woman pregnant. Can it lead to infertility problems? and can it harm the baby? Also, what does it mean if the guys balls are different sizes? is it bad? and can it affect being able to get a girl pregnant?
Any answers would be appreciated.

Several times before, I have gotten hit in the balls, and I was worried if this could cause infertility when I do decide to have kids.

Also, I was diagnosed with a hydrocele last year, even though the cause of the hydrocele was never found. I am afraid that the hydrocele may indicate a condition which will prohibit me from having kids.