stretching ears, help for a nub plz =)

I got my ears pierced a few days ago 16 gauge but i had to put in 18 gauge earings. My friends told me i only had to wait like a week or so before stretching them if i wanted. The lady at the place where ima buy my tapers also said my ears were healthy and healed enough to stretch. They arent swollen and dont hurt to move and rotate around. Should i start now? or give more tim to heal? And i do i was told i could stretch directly to 10 gauge, is this tru or is the lady at the place full of shit?