Is it normal to have bleeding and cramps after 3 days of complete miscarriage?

Yes, it's normal: I'm sorry about your miscarriage. As you've likely been told, having a miscarriage doesn't necessarily predict that you will have problems in a future pregnancy. Many women report bleeding similar to a period after a miscarriage. If the bleeding becomes excessive or if you feel lightheaded, seek medical attention immediately. Please be sure to follow up with your physician, as instructed.