Incubation period of pertussis is –
Pertussis 
After an incubation period of about 1-2 weeks, the disease takes a protracted course comprising three stages, - the catarrhal, paroxysmal and Convalescent - each lasting approximately two weeks.

B. pertussis infection
              ↓
Incubation period (1-2 weeks)
             ↓
Catarrhal stage (1-2 weeks)
             ↓
Paroxysmal stage (2-4 weeks)
            ↓
Convalescent stage (1-2 weeks but may last 1 to 3 months)
Remember

Catarrhal stage is the stage of maximum infectivity.
Maximum complications occur in Paroxysmal stage.
7 days
7–14 days
14–28 days
28 days