How long should I wait after PhD interview in Denmark?
As you already assume, it's likely that they have settled for another candidate. However, the fact that they didn't reply to your request indicates that they're not quite ready to dismiss you. Maybe their preferred candidate has not agreed to the position yet, and they want to keep their options.

The only thing you can do is write them another polite email, expressing your sincere interest and motivation to do the project, stating again why you think you are the best candidate. In case their first choice declines, you might be in for a good start. 

But in any case, I'd wait out Monday morning, assuming that that's the deadline the other candidate might have negotiated for a decision.