Total cost of inventory purchased. Where should I have entered it?

This is my first year selling on ebay. I started on January 1 so I started with zero inventory. Under Schedule C inventory/cost of goods sold I only put the inventory cost amount I sold. My question I have filed my taxes, but where should I have put my total so I would have a carry over? It asked enter cost of purchases I entered only the cost that I sold. Where should I have entered the total cost? I guess once my return is process and I get my refund I need to amend?