It usually takes between 7-14 days before symptoms of whooping cough appear after infection, although it can be up to 3 weeks. This is called the incubation period. The first symptoms are similar to a common cold. You may feel generally unwell with a runny nose, sneezing, a slight fever and a few days later, a dry cough. After a week or 2, the cough gets worse and you will have episodes of violent coughing which may end with a 'whoop' noise as you breathe in. Infants younger than 6 months are less likely to make the 'whooping' sound when they cough. Coughing is often worse at night, making it difficult for you to sleep.
Attribution: BUPA