What Causes Severe Body Pain And Dizziness Before The Periods?

Hi, I have taken regestrone-5mg for in last month to postpone y periods. This month its time for me to get chums. But I am experiencing very severe body ache and all other symptoms which I normally get before periods, but very severe this time. I am feeling very tired also, so tired that I feel sleepy while riding my two wheeler and I tend to doze off. Are all these due to side effeccts of the drug? Wat can be done?