You seem to be doing fine.
When my kids were that age... I put them down at certain times. I found that after about 2-3 hours of "awake" time, they got tired. Then I put them down to nap.
The key for me, was having a pre-nap and pre-bedtime routine. I did the same routine all the time. Then, as they get older... they are used to it already, and it really helps in preventing "protests" prior to going to sleep.
My boy, who is now 21 months old....STILL goes down for a nap at 9:00-9:30 in the morning, and in the afternoon at 2:30 or so. He naps for 2 hours each. Then at night, he does to bed at 8:00. I have done this with him since he was a baby...and throughout his various developmental "phases." He is so used to it, he gets tired at these times (his pattern, not mine), and he doesn't tantrum about it. He will even tell me when it is nap time, and goes about getting into his routine. Having a routine, for me, has thus been great!
Every child is different... go by your baby's pattern. I usually put my son down for nap, while he is still awake also, and he falls asleep on his own. So he's good that way.
Encourage your routine, if it works. Keep it up. No sense stir the pot and then have them get confused about it and then alter their sleep pattern. If what you have works, then great!
Most babies benefit from a routine...and just think down the road... if started now, you will more likely have a baby that is used to "napping".
*Sleep is important for them and their development. It's not just for Parents that they nap. It's for their development as well...cognitive and physical development.
My 5 year old even still naps, after she gets home from school. She likes it, and will even tell me "Mommy I'm going to nap now..."
Some babies will "force" themselves to keep awake, and then they get over-tired and fussy. Over-tired babies actually have a harder time falling asleep. Not all babies will sleep when they need to. Thus, for me, having a routine and keeping it the same everyday, has been very helpful in developing their sleep "habits." BUT... to get a routine stable... you need to keep it up... and don't vary it everyday. Keep it the same... keep it up... (I mean longer than just 1 week)...and OVER TIME... it will help, and the baby/child will get used to it.
I have seen this in my own kids. It worked for me.
They will have developmental "phases" that may cause temporary bumps in the road and they may not always go down...but still, keep up with the routine, the same nap time, everything....and after the "phase" passes, it will return to their regular sleep pattern. At least this is what I've seen with both my children.
You seem to be doing fine. This is just what I've done with my kids.
All the best,
~Susan