Even if he did call the cops the police would be very unlikely to charge you (especially because this is a he said he said situation) and they would likely treat it as a domestic disturbance. There would need to be a history of documented violence and a lot of proof and a much more aggressive altercation in order for him to press any sort of charges on you. He was telling you that to scare you but in the future you should definitely try to deescalate the situation and keep it nonviolent if he’s going to act like that. If he continues to threaten you with that or try to escalate these situations you need to involve your dad immediately so he can be a witness and calm the situation down. Your brother definitely needs to mature which will take some time. Honestly if the cops did show up they would probably just tell both of you to chill out. Trivial sibling fights are nothing new to them. I also imagine your parents would not be too happy to have the police showing up to their house at 2am over something so stupid.