It is very unlikely that you are pregnant if you experienced a normal period after completing your course of Duphaston (dydrogesterone). This bleeding is typically a sign that your uterine lining has shed. The dizziness and stomach cramps you are feeling now are quite common and are likely related to normal hormonal fluctuations or your menstrual cycle itself. However, because early pregnancy bleeding can sometimes mimic a period, the most reassuring step is to take a simple home pregnancy test. Please rest, stay hydrated, and consult your doctor if your symptoms persist or worsen.