Drain the can of blueberries, reserving the juice. Set aside 1/3 cup of the blueberries. Puree the remaining berries and 1 tablespoon juice in a blender. Fold in the reserved berries. In a small bowl, whisk the yogurt with the milk. In pop molds or 3-ounce paper cups, alternate 2 rounded tablespoons of the yogurt mixture with 1 tablespoon of the blueberry mixture. Swirl with a knife. Cover and freeze.