2 or 3 days ago my buddy found it funny to punch me in the nuts (I'm 16, boys will be boys, I guess)

The day of or the day after I ejaculated and it hurt the tip of my penis. I didn't think it was that big of a deal until the day after I ejaculated again and there were what seemed to be blood droplets in each "shot" (?) of seamen. (no pain this time)

I'm guessing there is some internal bleeding, could this heal itself? and if so how long should it take to heal or how long should I put sexual activities off for? Obviously if it doesn't stop I will go see a doctor but it is quite akward asking the parents so thats why I thought I'd come here first.

The punch wasn't that hard but I guess he must've hit a vein or something pretty accurately.

Thanks for any help.

EDIT: Also there is no pain when I touch either my balls or my penis.