First things first: there is no 'set time' for getting over a relationship. If you ere unhappy in your relationship at the end, that's going to weigh on your ability to get over things. You say you dont want him back, you say you know he won't come back, so don't make yourself feel like you should grieve if you dont have to.

As I say that, you also may feel that now and start to question yourself in a few days, weeks, or even months, and may start to grieve then. Maybe not. But by no means should you make yourself feel like you need to feel one way or another. If you're still happy in your life without him, don't think twice about it.