Remember when Samus gets off her space ship at the beginning of the game and u start the game? If you do go back to the place where Samus's space ship is, once you’re there go on top of it and go over to the glowing thing. After you've saved your game it will say, full health and ammo replenished, do this only if you don't want to go all the way to dark anther to get your ammo replenished.