Is it normal to have my ball hurt sometimes?

No.
Pain is your body telling you that something is amiss.
It could simply be that our body is healing itself from a strenuous workout or it could be something more.

I cannot say without knowing more.

maybe it's nut cancer.

Could be normal.

Do they hurt after sex or masturbation? That's pretty common if you are rough and hitting the testicles against something (or someone) they will hurt afterwards.

Equally if you get sexually aroused, precum, but to do not ejaculate that may cause semen to become trapped in then ducts, which can be painful. You usually pee it out or ejaculate to clear it.

That's basically blue balls, you get very aroused but don't get off. If you're like a young teen and never masturbated but often get aroused/a ***** that could be your problem.

if you're in puberty maybe, because it's dropping and growing into a big strong grown up ball. if you're older then now, it's nut cancer, get the fvcker chopped off.

I shouldn't have clicked this.

Ever heard some say "play with it too much and it will fall of"?