Preheat oven to 200C. Grease and flour muffin tray or use paper liners.
Mix the flour, oats, sugar, baking powder, salt, cinnamon and nutmeg together in a mixing bowl until evenly blended. In a separate bowl, stir together the pumpkin, milk, egg and butter. Gradually stir in the flour mixture just until all ingredients are moistened. Fold in the blueberries. Spoon batter into muffin cups, filling to the top.
Bake in preheated oven until tops spring back when lightly pressed, about 20 minutes.