If the scan is fine and shows that the fetus is healthy then you neednt worry much.The cough is the problem here. You need to avoid any kind of stress on the abdomen. Coughing,sneezing, straining, bending etc can all increase the intra-abdominal pressure. That cause stress on the pregnancy in some women,have a tendency to bleed. You are just out of the 1st trimester, so you arent completely safe at the moment.You need to make sure you have complete rest and avoid putting unnecessary strain.Take treatment for the cough.