I would not get a new battery if I were you.
I would wait to not start and have AAA come save me like faz did (j/k).

I'm assuming by OEM battery you mean the original battery it left the factory with. Otherwise it could be an OEM replacement battery installed by the dealership 6 months ago. Even if it is the original this thing could go on for another couple of years. Save the money now and spend it when you need it. But if you've got the cash just burning a hole in your pocket to be spent on something as cool as a new battery then go for it.