E.E.
Is he happy? (Relatively I mean).
If he's happy, I wouldn't worry about it too much. My guy didn't start sleeping longer (and long for him is still only 45 minutes) until 3-4 months.
And still, if he closes his eyes at all (even for a 5 minute car ride) that's considered a nap.
He's still so young, he's finding his way, I'd say. And if I were you I'd cherish the 9-10 hours at night!! I still don't get that!
But...is he napping in the same place he sleeps at night? Do you make the room as dark as possible? Could he be too hot/cold?
Good luck!