The normal range for amniotic fluid levels can vary, but generally, a measurement of 11 at 28 weeks falls within the normal range. However, it's important to consult with your healthcare provider for a more accurate assessment. They will consider other factors such as your overall health and any symptoms you may be experiencing. If there are concerns about low or high amniotic fluid levels, further tests may be recommended to ensure the well-being of both you and your baby.