Well they would have to tell you if they did the hep B. If they did, they would assume you are going to continue with the rest of the shots. The rest of the hep B schedual depends on whether your child got the shot at birth or not.
My first child was supposed to get the hep B at the hospital and they messed up and didn't (thank goodness). They sent me a letter later (or called my dr. I forget which) and let us know about the mistake. When I took her to the health department for her 2 month shots, they asked about it.
With my second and third children I just told them I wanted to skip the shot at the hospital and would get it at the 2 month shots. (doesn't mean you have to

)