How did you handle stairs?

Hi all,

I have a 3 month old bernese. Everything I've read, and the breeder, say to avoid stairs for atleast a month after bringing him home. I have five steps up to my porch, I have been carrying him up and down them. The vet yesterday said stairs are fine and he should be doing them to build tendon and muscle strength? Im getting conflicting information. I would love to hear feedback on how everyone else handled stairs and how your matured bernese is now