Baby carrier as main form to transport baby..

Gl

I live in the city and trains and buses are always full and don't to be the one to squeeze in. Also I don't want to have to lug a stroller up and down stairs. Is it okay if I use a baby carrier to take baby to appts or wherever we go? I intend to use carrier from when I bring baby home. Also he'll be a winter baby we won't be going out that much.