Yes, you can consume milk, dates, and dairy fruit mix juice during your 21st week of pregnancy. There is no harm in consuming them together. In fact, they provide essential nutrients for both you and your baby. Milk is a good source of calcium and protein while dates are rich in fiber and natural sugars. The combination of these foods can be beneficial for your overall health. However, if you have any specific concerns or dietary restrictions, it's always best to consult with your healthcare provider for personalized advice.