Normally they will be up at the end of teething, usually around 6 - 7 months of age.
It is extremely uncommon for a 3 month old to have fully erect ears. If the puppy is very small they may stand earlier but most are soft and floppy until around 6 months of age, and even those whose ears did stand early tend to flop during the eruption of the adult teeth.
However, genes play a part as well, and if the parents ears did not stand naturally, the puppy has a greater chance of having a floppy ear or ears as an adult.
Right now he sounds perfectly normal for his breed and his age.

Toto, CD, RN, CGC answered on 1/20/13. Helpful? / 1