I've had scarlet fever five times when i was younger. Could i get it again? even though im 16 now?

I got it when i was in kinder,2,3,4 and 6 grade im in 11th and my little brother is getting the symptoms could get it{Scarlet fever}

yes you can. Infections can remain dormant in your body and when your body immune system is weak or you have just been sick your body will no longer be able to fight it off and especially since your exposed to it it is a possibility avoid direct contact, wash hands frequently and don't share drinks or food or be in contact with any thing he touches or sleeps in or with ( meaning teddies or blankets or his bed)where he does make sure you wash his blankets and clothes in hot water and replace his tooth brush and sanitize what he touches this will avoid you checking it

I am thinking if you get proper antibiotics whithin a reasonable time of being sick you wouldnt get scarlet fever. Am I right? I thought it was caused by strep left untreated.

I'm surprised to hear you had scarlet fever five times. Most usually, if you actually have scarlet fever once you are highly unlikely to get it again. It's a bacterial infection, and adequately treated the body usually has resistance to prevent it happening again. A lot of throat infections actually are viral in origin, though, and viruses often do cause rashes that can be confused with the scarlettina rash of scarlet fever. Since you say you actually had it five times already, I think this question would be best put to your family doctor.