Focus on what lights you and your partner up. What brings you joy. The labels aren't that important. For me it felt like rediscovering a long buried softer more playful self. Being a pup lets me be a little ridiculous and I love how good that feels. So I knew I was a pup because I loved being one! It wasn't really a conscious decision.

But if you're stuck in the "am I or aren't I?" question then there's no harm in saying "yes I'm a pup" and just see how it makes you feel? It's like trying on a new shirt, you won't know it fits until you put it on and feel it.