Period with severe lower abdominal pain.

Hello, Hope you are doing well. We are consulting a doctor for my wife's pregnancy. As per the suggestion We tried having intercourse from 16th to 25th of her periodic cycle this month. Also as per the doctor suggestion she was taking susten daily @night starting from 16th day of her periodic cycle. And follic acid tablets in the morning. Her period suddenly started from yesterday with severe stomach pain.(which was 4 days early) She was unable to bear the pain even with pain killer.(She takes  drottin M). And her period stopped today after only 1 day. Befere the day she started having period she saw mild  pink discharge. Can you please help me understand her situation and possibly point me to the next course of action. Any help will be really helpful.