That's scarcely enough information for even a doctor to tell you whether you have had a miscarriage. Were you even pregnant or are you just guessing? Sounds more like just a bad period. A doctor would want to know how long you've been on the pill, whether you've recently changed prescriptions. Have you had any gyno typre problems before, your menstrual history. If you are pregnant are have reasonable basis to believe you are, you should check with your doctor.