Aah, I understand the worry lah! Honestly, at 3 months, as long as he's sleeping well at night and seems happy and alert during the day, those frequent 20-30 min naps are actually quite normal for some babies, every baby is different. A few of my mum friends have babies like that too, and their paediatricians said it's fine as long as the total sleep (day + night combined) adds up. That said, definitely mention it to your paediatrician next visit so they can check if everything else is on track, sometimes longer naps come naturally as they grow, sometimes they don't, and your doctor can give you peace of mind based on his weight gain and development. How's he during the day otherwise, is he cranky or seems well-rested?