We have warehouses in different parts of the country where each one has a different amount of inventory of an item. If one of the items you ordered is out of stock in the warehouse nearest to you, it may shipped from another. This may cause one of the items to arrive sooner than the other.
Rest assured your other item will reach your home soon enough. If you want to track it down, visit your Shapermint Account by clicking this link.
If you need more info about the order status, you can find answers in this article.
If you feel that you should have already received all of your items, please Contact Us.