Actually it's fine to take it later. Baby is not likely to be sick or infected by staying at home for a long time. Unless your house is full of people then please take it soon.
I drag and delay and mine is a 20 months old now, never fall ill in his entire life yet. He still got some vaccinations not yet taken.
Anyways before you go, check if they have stock for the vaccine. This is the main reason of my delays.

Oh, the usual place I goes to, they don't keep alot of stocks.