Should I buy some formula even if I plan to breastfeed?

Am about to give birth and I plan to breastfeed. Am packing my hospital bag and wonder if I should buy some milk for the journey home and the first days in case breast milk doesn't come in?

UPDATE: Thanks everyone for the good advice. Am putting it all into action.

One last question. Does colostrum always come in? Am 38 weeks and I have never leaked anything. My breasts did not change in size but my nipples are protruding.