Aw, 15 months pa lang yan, marami pang may ganyan na timeline, one of my mum friends' baby didn't get teeth until almost 18 months at normal lang naman! Pero since it's a development thing, better check with your pedia just para ma-rule out if may underlying issue, okay? Some babies talaga ay late bloomers with teeth, pero it's good peace of mind na marinig from your doctor directly.