When to buy breast pump?

AmberMR10

I recently decided to breastfeed. I originally thought to buy a pump before the baby is born. But I got to thinking about it, what if the baby doesn't take breast feeding and then I would have already spent money on a pump? I just don't want to buy one and then the baby doesn't want to breast feed? So do you suggest I wait to buy a pump, or just buy one before the baby is born? Thank you!