Might help to check the trunk of your car. Same thing has happened to me. Turned out I didn't leave it at the supermarket. I just didn't grab all the bags out of the trunk.
I put my grocery bags on the floor in the backseat area of my truck. Several times I've later heard things rolling around and found apples or pears that rolled out of the grocery bags.
BBQ-Nut, I've left things at the grocer and just called and they usually have it at customer service.