coughing problems at around 20 weeks

Hi there mommies! I am having a mild cough and I think this cause pain in my lower abdomen. Any suggestions in treating mild coughs? I'm so worried. I am also a bit experiencing difficulty in walking, its like its very on my abdominal part. Any same experiences here. By the way, my ob prescribed me Duvadilan but I haven't yet bought one. Just about to buy and take this morning.