DD just coughed (once) and at the end she made a whooping sound which made me think of the whooping cough. She's been coughing a bit, no mad bouts of coughing just once every now and then. I don't think she has any other symptoms. Do babies cough with the whooping sound randomly sometimes? She's only done it the once so I don't know whether to start worrying or not. I'm a highly anxious person.