When is/are the right time/s to ask where the relationship is going? How do I know whether I’m only adding unnecessary pressure to a good thing by asking?
"Where is this relationship going?" is a horrible fucking question that puts your partner on the defensive. It’s a needy and self-defeating expression of weakness and insecurity. Don’t ask it.
Instead, try an expression of vulnerability. “I think I’m starting to fall in love with you,” can prompt the kind of conversation you want to have without backing your partner into a corner.
If you have a little strength of character, you can also just say what you’re thinking. Go ahead. Try, “I want things to get more serious.” After all, you should have as much input as your partner about where the relationship is going.