To make the custard, combine milk, eggs and sugar (I used a blender).
Heat a pan to medium high heat, then add in the milk mixture. Stir constantly so it doesn't scorch.
Once the mixture is bubbling, cook for another 2 minutes or until thickened. Set aside.
In a blender, combine blueberries, yogurt, and vanilla flavoring. Blend until smooth.
Mix the blueberry flavoring with the custard until combined, then put in the refrigerator for a few hours.
Add the mixture to an ice cream maker, then slowly add in the whipping cream.
Keep in the ice cream maker until it is hardened, then serve!