Just to echo what Spaniard said... you should be feeding once per week, not once every 2 weeks. Many people here suggest feeding small snakes that are actively growing on a 5 day schedule rather than a full week. Spaniard spoke of one of two methods to decide on prey size. Another way to judge proper size is to feed roughly 10% of the snake's weight. This is how I choose to do it. Finally, multiple prey items is ok as long as the total equals the proper size for the snake (if feeding live prey, please feed one item at a time).
Steve