What Causes Delayed Periods And Uneasiness In Lower Abdomen?

I had a miscarriage 6 April 2010. On 4th May 2010 i had my period with little discharge. Now today is more than a month has passed and i am expecting my next periods, but it has not come yet. Presently i am feeling uneasiness in my lower abdomen and i am having some white discharge also.What may be the reason and what should i do? Pls suggest !!