What happens when a women is not tested to see if she's pregnant before they give her birth control and it results in her having a miscarriage?

Usually one doesn't involve the other in testing requirements. However, it may also be the case that the woman doesn't know she is pregnant or the pregnancy hormones haven't resulted in positive results such that whatever the doctor gace was based on the information the doctor had at the time. If the miscarriage was not too far along, you would have had to have a medical diagnosis that the miscarriage was directly related to taking the pill and that the doctor committed malpractice by not properly testing you prior to prescribing the pills.