My 2 year old is having coughing fits that last 30 seconds to a minute and a half. He gasps for air during the fit and he has a hard time catching his breath immediately after the coughing fit. He has had cold like symptoms including runny nose, watery eyes, irritability, slight cough, and is tired, for about 2 weeks. He seems to be fine during the day but evening and night time the symptoms are worse. I originally thought the cough sounded like croup but after doing some reading im not sure if this could be whooping cough. How would i tell the difference and does he need to be seen by a doctor?