When to transition to 2 naps?

When did you know when to transition your LO to 2 naps? My LO is 6 months and he used to take 2 longer naps and one cat nap in the late afternoon but the last few days all his naps have been only 30 mins. Is this a sign that it is time to transition him to 2 naps? He is teething as well so that could be interfering with his naps. I have played with keeping him awake longer or even putting him to sleep 15 minutes earlier but it still resulted in a 30 minute nap. The last 2 days he took 4 30 minute naps because he was exhausted. Not sure what to do... FTM. Suggestions would be great! Thank you 😊