After the quarrel, my boyfriend ignored me and sent him a message. He didn't reply to this message. He/kloc-hasn't contacted me for 0/6 days. Is it a breakup?

If there is no contact after 16 days, it can be said that we have broken up. Your current situation is equivalent to silently breaking up and not contacting. I won't give the other party the final explanation. In fact, this is also the reason why your boyfriend wants to break up with you resolutely, because he hasn't contacted you for 16 days, and he never calls you back when you send him a message. Maybe he blocked you. When you send a message, he doesn't even bother to open the message you sent him. He may delete you in a few days. In fact, you two have already broken up by default, and there is no need to continue to entangle.